This page is dedicated to helping those who are taking exams based on hand fitting and basic machining.

There will be essential information on the tools, techniques, and processes that are undertaken in a workshop.

KEY LEGISLATIONS:

  • The Health and Safety at Work etc. Act 1974 (HASAWA) is the primary piece of UK legislation that regulates occupational health and safety. Its main objective is to ensure that employers take responsibility for the health and safety of their employees while at work.

    HASAWA requires employers to provide a safe working environment by identifying and controlling hazards and risks, providing adequate training and supervision, and ensuring the welfare of their employees. It also requires employees to cooperate with their employers and follow health and safety rules and procedures.

    The key provisions of HASAWA include:

    1. Duties of employers to ensure the health, safety, and welfare of their employees.

    2. Duties of employees to take reasonable care of their own health and safety and that of others who may be affected by their actions.

      3. The requirement for employers to carry out risk assessments to identify hazards and implement appropriate measures to control risks.

      4. The establishment of the Health and Safety Executive (HSE) to enforce the law and promote good health and safety practices.

      5. The provision for penalties and enforcement measures for non-compliance with the law.

    Overall, HASAWA is a crucial piece of legislation that ensures the protection of workers' health and safety in the UK.

  • RIDDOR (Reporting of Injuries, Diseases and Dangerous Occurrences Regulations) is a UK law that requires employers, the self-employed, and those in control of premises to report certain work-related accidents, diseases, and dangerous incidents to the Health and Safety Executive (HSE) or the local authority. The main aim of RIDDOR is to improve the prevention of accidents and diseases in the workplace by providing a systematic reporting and investigation mechanism.

    Under RIDDOR, employers and other responsible parties must report the following incidents to the relevant authority:

    1. Deaths or injuries that occur as a result of work-related accidents, including those resulting from violence, physical or mental strain, or exposure to harmful substances. 2.

    2. Certain work-related diseases, including those caused by exposure to harmful substances or biological agents. 3.

    3. Dangerous incidents, such as gas leaks, electrical failures, or explosions that could cause serious harm or damage.

    The reporting requirements vary depending on the type of incident, but in general, reports must be made as soon as possible after the event and within specific timeframes. Failure to report an incident that is required by RIDDOR is a criminal offense and may result in penalties.

    Overall, RIDDOR plays a crucial role in the prevention of accidents and diseases in the workplace by ensuring that incidents are reported and investigated, leading to improvements in health and safety management.

  • COSHH (Control of Substances Hazardous to Health) is a UK law that requires employers to control exposure to hazardous substances in the workplace to prevent ill health. The aim of COSHH is to protect workers from exposure to chemicals, fumes, dust, and other harmful substances that could cause diseases, injuries, or other health problems.

    Under COSHH, employers must:

    1. Assess the risks posed by hazardous substances in the workplace.

    2. Implement control measures to prevent or reduce exposure to hazardous substances, such as providing ventilation or personal protective equipment.

    3. Provide information, instruction, and training to employees on the risks associated with hazardous substances and how to use control measures.

    4. Monitor exposure to hazardous substances and carry out health surveillance where necessary.

    5. Prepare plans and procedures for dealing with accidents and emergencies involving hazardous substances.

    COSHH applies to all industries and sectors that work with hazardous substances, including manufacturing, construction, healthcare, and cleaning. Employers must ensure that they comply with COSHH regulations, including carrying out regular risk assessments and implementing control measures to protect their workers' health.

    Overall, COSHH plays a crucial role in ensuring that workers are protected from the harmful effects of hazardous substances, leading to improved health and safety in the workplace.

  • PUWER (Provision and Use of Work Equipment Regulations) is a UK law that requires employers to ensure that work equipment is safe and suitable for use by their employees. The aim of PUWER is to prevent accidents and injuries caused by unsafe work equipment and machinery.

    Under PUWER, employers must:

    1. Ensure that work equipment is suitable for its intended use and is maintained in a safe condition.

    2. Ensure that work equipment is inspected and tested regularly to identify any defects or faults.

    3. Provide adequate information, instruction, and training to employees on the safe use of work equipment. 4

    4. Ensure that work equipment is used only by competent persons.

    5. Ensure that work equipment is fitted with appropriate safety devices and warnings.

    PUWER applies to all work equipment, including machinery, tools, and vehicles, used in any workplace. Employers must ensure that they comply with PUWER regulations, including carrying out regular inspections and maintenance of equipment, to prevent accidents and injuries to their workers.

    Overall, PUWER plays a crucial role in ensuring that work equipment is safe and suitable for use, leading to improved health and safety in the workplace.

Health and Safety basics

Working in a hand fitting/machining workshop can pose potential hazards to your health and safety. Here are some essential health and safety guidelines you should follow:

  1. Wear Personal Protective Equipment (PPE): Always wear appropriate PPE, such as safety glasses, ear protection, dust masks, and gloves, to prevent injuries or health issues from exposure to dust, debris, noise, or chemicals.

  2. Follow Safety Procedures: Make sure you are familiar with the safety procedures in your workshop and follow them at all times. Be mindful of the safety warnings, such as the proper handling and storage of materials, tools, and equipment.

  3. Keep Your Work Area Clean: Keep your work area clean and tidy to prevent accidents or injuries. Sweep up debris and put away tools and equipment when not in use.

  4. Use the Right Tools: Use the right tools for the job and make sure they are in good condition before using them. Follow the manufacturer's instructions for use, maintenance, and storage.

  5. Maintain Equipment and Machinery: Maintain your equipment and machinery regularly to prevent malfunctions or breakdowns that could cause injuries or accidents.

  6. Avoid Loose Clothing and Jewelry: Avoid wearing loose clothing and jewelry while working in the workshop. They can get caught in machinery or cause accidents.

  7. Take Breaks: Take breaks and rest regularly to prevent fatigue or injuries from repetitive tasks.

  8. Keep First Aid Kit Handy: Keep a first aid kit handy and know how to use it in case of an emergency.

  9. Seek Medical Attention: Seek medical attention immediately if you experience any symptoms, such as dizziness, shortness of breath, or nausea, while working in the workshop.

Hand Tools

Hand tools are essential components of any manufacturing workshop. They are handheld devices that are powered by the force of the user's hand and are used to perform a variety of tasks. These tools are designed to be easy to use and require minimal maintenance, making them an ideal choice for students and professionals alike.

Using hand tools requires a certain level of skill and knowledge, as well as the proper safety equipment. It is essential to use hand tools correctly to prevent accidents and injuries. Students who plan to work in a manufacturing workshop should familiarize themselves with the different types of hand tools and how to use them safely and effectively.

Overall, hand tools are an essential part of any manufacturing workshop and are used every day by professionals and students alike. Whether you are tightening a bolt, cutting a piece of metal, or holding an object in place, the right hand tool can make all the difference in the world.

The File:

Taps & Dies

NOT THAT TYPE!!

Thats better!

Tap Wrench

This is what the majority of dies look like. You can see the size of the thread it is going to cut by the 12mm and 1.75.

It will be a M12 x 1.75 pitch

A hack saw is a tool commonly used in metalworking for cutting metal objects such as pipes, rods, and bars. Its purpose is to make precise cuts in metal using a blade that has small, sharp teeth.

Some of the common uses of a hack saw in a metal workshop include cutting metal pieces to size, making angled cuts or notches, and cutting off unwanted sections of metal. It is also commonly used for cutting through smaller or thinner pieces of metal that might be difficult to cut with other tools.

Hack saws are versatile and useful tools in a metal workshop for cutting metal with precision and control.

Safety tips

Tap Wrench in a different style

Replacing blades

  1. Loosen the tension: Locate the tensioning knob or lever on the saw frame and loosen it to release the tension on the blade.

  2. Remove the old blade: With the tension released, remove the old blade from the saw frame by sliding it out of the blade guide.

  3. Prepare the new blade: Ensure that the new blade you want to install is the correct one for the material you are cutting. You should also ensure that the teeth are facing in the correct direction.

  4. Insert the new blade: Insert the new blade into the blade guide, aligning the teeth with the cutting edge of the saw frame.

  5. Tighten the tension: Use the tensioning knob or lever to tighten the blade to the appropriate tension. You should be able to press the center of the blade and deflect it slightly, but it should not bow out from the saw frame.

  6. Check alignment: Check that the blade is aligned correctly in the blade guide, and that the teeth are facing in the right direction. Ensure that the blade is not rubbing against the saw frame.

  7. Test the blade: Finally, test the new blade by making a few test cuts to ensure that it is cutting smoothly and efficiently.

A Lapping machine in action

What are some common applications of scraping and lapping?

In the automotive industry, scraping and lapping are used to create high-precision engine components such as cylinder heads and crankshafts.

In the aerospace industry, these techniques are used to create critical components such as turbine blades and fuel nozzles.

In the medical industry, scraping and lapping are used to create precision surgical instruments and implants.

Metal files are hand tools used for shaping, smoothing, and finishing metal, wood, or other materials. They consist of a hardened steel blade with abrasive teeth or ridges, called "cuts," that are designed to remove material from the workpiece.

Descriptions of files will frequently refer to ‘cut’, which describes the pattern of the teeth on the working part of the file (Single or Double cut). The different spacing of teeth can be measured by “Teeth per inch”

Different types of metal files include flat files, round files, half-round files, triangular files, and needle files. Each type is designed for specific tasks, such as shaping corners, smoothing curves, or creating grooves.

The choice of file type and cut depends on the material being worked on, the level of precision required, and the desired finish. A general rule of thumb is to start with a coarse file and gradually work up to a finer file for a smoother finish.

Thread-cutting taps are hand tools used to create internal screw threads in a variety of materials, including metal, plastic, and wood. They are typically made of high-speed steel and have cutting teeth that gradually carve out the thread as the tap is turned into the material.

The difference between 1st, 2nd, and 3rd taps refers to the level of accuracy and finish of the threads they produce.

First (or roughing) taps have larger and deeper teeth that remove material quickly and are used to create the initial thread. They are the least accurate and have the roughest finish.

Second (or intermediate) taps have smaller and shallower teeth that refine the thread and remove any excess material left by the first tap. They produce a more accurate thread with a smoother finish.

Third (or finishing) taps have the smallest and finest teeth that further refine the thread and produce the most accurate and smoothest finish. They are typically used for high-precision applications.

The choice of tap depends on the material being threaded, the required thread accuracy and finish, and the size and type of tap needed. It is important to use the correct tap for the job to ensure the thread fits and functions properly.

Metal dies are hand tools used to create external screw threads on rods or bolts made of metal or other materials. They are typically made of high-speed steel and have cutting ridges that carve out the thread as the die is turned onto the rod.

The purpose of metal dies is to produce threads that are uniform in size, pitch, and angle, ensuring a precise fit with a corresponding nut or threaded hole. Dies come in different sizes and thread pitches to accommodate various rod sizes and thread types.

To use a die, the rod is first secured in a vice or other holding device, and the die is placed over the end of the rod. The die is then rotated clockwise, cutting the thread onto the rod. A die handle or wrench is used to turn the die and apply the necessary pressure.

Metal dies are commonly used in manufacturing, repair work, and DIY projects where threaded parts are required. They can be used to repair damaged threads, create custom threads, or add threads to rods or bolts that do not have them.

It is important to use the correct size and type of die for the job, as well as the appropriate lubrication to prevent damage to the die or the threaded rod.

  1. Wear appropriate safety gear: Always wear eye protection, gloves, and other appropriate safety gear when using a hack saw.

  2. Choose the right blade: Use the appropriate blade for the material and thickness you are cutting.

  3. Check the blade: Inspect the blade for damage or wear before use. Replace it if it is dull, bent, or damaged.

  4. Secure the material: Secure the material you are cutting in a vise or clamp to prevent it from moving while you work.

  5. Keep fingers clear: Keep your fingers clear of the blade and cutting area at all times.

  6. Use proper technique: Use a smooth, steady motion when cutting, and avoid pushing or pulling too hard on the saw.

  7. Take breaks: Take frequent breaks to avoid fatigue and maintain concentration.

Scraping and Lapping

What is scraping and lapping?

Scraping is a process that involves using a hand-held tool to remove small amounts of material from a surface to achieve a high degree of flatness and precision. Lapping, on the other hand, involves rubbing two surfaces together with a fine abrasive to remove material and create a polished finish.

We mainly scrape and Lap components to ensure they are a good fit with other components

How is scraping and lapping used?

Scraping and lapping are used in a wide range of industries, including automotive, aerospace, and medical, to create high-precision parts and components.

They are often used to ensure that parts fit together precisely, reducing friction and wear, and improving performance and longevity.

Die Holder

Hack Saws

A normal (bigger) and junior (smaller) hack saw

Selecting a blade

The selection of the blade to use with a hack saw depends on various factors such as the type of material being cut, the thickness of the material, and the desired finish of the cut. Here are some general guidelines to help you choose the right blade for your needs:

  • Different materials have different hardness and require different blade types. For example, a high-speed steel blade is suitable for cutting softer materials like aluminum, while a bi-metal blade is better suited for cutting harder materials like steel.

  • The TPI of a blade refers to the number of teeth per inch of the blade. A blade with a higher TPI will produce a smoother finish but will cut slower. A lower TPI will cut faster but produce a rougher finish. Select a blade with the appropriate TPI for the thickness of the material being cut.

  • The thickness of the blade can also affect the quality of the cut. Thicker blades are more durable and produce straighter cuts but require more force to use. Thinner blades are more flexible and better suited for curved cuts but are less durable.

  • The length of the blade should be appropriate for the material being cut. A longer blade will cut straighter but may be difficult to maneuver in tight spaces.

Scraping in action

What are the benefits of scraping and lapping?

By creating a flat, even surface, scraping and lapping can improve the accuracy and precision of machine parts, leading to better performance and reliability.

Scraping and lapping can also help to reduce friction and wear on parts, which can extend their lifespan and reduce the need for maintenance or replacement.

Additionally, by creating a smooth, polished surface, lapping can improve the aesthetic appearance of parts, making them more appealing to customers.

How does the scraping and lapping process work?

The process begins by selecting the appropriate tool and abrasive material for the job.

The operator then carefully removes material from the surface using the tool, checking the flatness and precision of the surface with precision measuring tools such as micrometers and dial indicators.

Lapping involves rubbing two surfaces together with a fine abrasive, often in a circular or figure-eight pattern, until the desired finish is achieved.

The bottom tap is the 1st tap, you can tell from it’s tapered top. Moving up, the middle is the 2nd and the top one is the 3rd tap.

Dies

Tap & Die holders

Both taps and dies are normally used with special holders to allow the user to apply rotational force to cut threads

Measuring tools and techniques

Measuring tools are instruments used to quantify or measure physical quantities like length, height, width, depth, and diameter, as well as other physical attributes such as angles, surface roughness, and temperature. In an engineering workshop, measuring tools play a vital role in ensuring that the manufactured products meet the required specifications and tolerances. Without proper measuring tools, it would be impossible to manufacture products with the required precision and accuracy.

The use of measuring tools is not limited to the engineering workshop; they are also used in various other industries such as construction, manufacturing, research and development, and quality control. In addition, measuring tools are also used in everyday life, such as measuring ingredients for cooking or measuring distances while driving.

Different types of measuring tools are available, each designed to measure specific physical quantities or attributes. Some common measuring tools used in an engineering workshop include calipers, micrometers, height gauges, dial indicators, thread gauges, surface roughness testers, and temperature sensors.

The importance of measuring tools cannot be overstated in the manufacturing industry, where even the smallest deviation from the required specifications can lead to significant quality issues, product failures, or even safety hazards. Therefore, it is essential to choose the right measuring tool for the job and to ensure that it is calibrated and maintained appropriately.

Calipers:

Calipers are measuring instruments used to measure the distance between two opposite sides of an object. They can be either vernier, dial, or digital, with vernier calipers being more traditional, digital calipers being more modern, and dial calipers being a bit rarer. They are commonly used to measure the diameter of holes, the thickness of objects, and the distance between two surfaces.

Common Measuring Tools

Micrometers:

Micrometers are precision measuring instruments used to measure small dimensions accurately. They are available in two types: inside micrometers and outside micrometers. Inside micrometers are used to measure the internal diameter of holes, while outside micrometers are used to measure the diameter of objects. They are commonly used in the manufacturing of small parts and components.

Height Gauges:

Height gauges are measuring instruments used to measure the height of objects. They are commonly used in the manufacturing of parts and components where precise measurements are essential. They can be either vernier or digital, with digital height gauges being more accurate and efficient. Another use can consist of having a blade on the measurement part of the height gauge that can scribe material.

It is essential that when you are using a height gauge, the base of the gauge and part you are measuring is on a flat reference point.

Squares:

Engineers squares are used to accurately check and mark angles, or to verify the squareness of straight edges and lines. High-quality squares are precision made to form a perfect 90-degree right angle, against which you can test all manner of edges, planes and corners on a workpiece.

Surface plates and tables:

A surface plate is a flat and level tool used in manufacturing and machining processes to provide a precise reference surface for measuring, marking, and inspecting the flatness, parallelism, and squareness of workpieces and tools.

Surface plates are typically made of granite, which is stable, durable, and resistant to wear and corrosion. They come in various sizes, shapes, and grades of accuracy, ranging from small hand-held plates to large floor-mounted tables.

Standards:

Measuring surface finish

Vernier Caliper

Outside Micrometer

Inside Micrometer

DTI (Dial test Indicators)

Dial test indicators gather accurate readings by using an extremely sensitive arm that sweeps at an angle. It measures exactly how far the arm is pushed sideways to provide an accurate reading of relative motion. In simpler terms, they are used for converting minuscule lateral movements into a rotary dial reading.

Tolerance:

Surface finish gauge

Surface roughness tester

In manufacturing, surface plates are used in conjunction with precision measuring tools such as height gauges, dial indicators, and micrometers to ensure that machined parts are within specified tolerances and meet quality standards. Machinists use surface plates to set up and align machines, fixtures, and workpieces, and to check the flatness and parallelism of surfaces that are critical to the performance of the final product.

Overall, surface plates are essential tools in manufacturing and precision machining, as they provide a stable and accurate reference surface for the measurement and inspection of workpieces, ensuring that they meet the required specifications and quality standards.

In manufacturing, tolerance refers to the allowable variation or deviation from a specified dimension, shape, or material property of a product. Tolerances are essential because no manufacturing process is perfect, and there will always be variations in the finished product's dimensions or characteristics.

Tolerances are specified in the design and engineering phase of the manufacturing process to ensure that the finished product meets the required specifications and performs as intended. Tolerances can be expressed in various forms, such as linear dimensions, angles, surface finishes, material properties, and electrical properties.

Limit of size

The “limit of size" in manufacturing refers to the maximum or minimum acceptable dimensions of a part or component in a given manufacturing process. The limit of size is typically specified as a range of acceptable dimensions that a part or component must meet to be considered acceptable for use in an assembly or system.

The limit of size is determined by various factors, including the design requirements, the manufacturing process capabilities, and the intended use of the part or component. For example, the limit of size for a machined part may be influenced by the tolerances of the machining equipment, the properties of the raw material, and the required functionality of the finished part.

Contact methods:

  • Surface finish gauge: This is a set of gauges with known surface finishes that can be used to compare and rate the roughness of a surface. The operator matches the surface finish to the closest reference plate to determine the surface roughness value. Normally by scratching each surface.

  • Surface Roughness Tester: This is a handheld device that uses a stylus to scan the surface and displays the roughness value on a digital screen. It is portable and easy to use, making it ideal for on-site inspections.

How a laser would scan surface finish

Types of fits.

  1. Clearance fit: In a clearance fit, there is intentional clearance between the mating parts. The minimum size of the hole is larger than the maximum size of the shaft, providing a gap or space between them. This type of fit allows for easy assembly and disassembly and is often used when relative motion or adjustment is required between parts.

  2. Transition fit: A transition fit falls between a clearance fit and an interference fit. It provides a balance between clearance and interference. The parts may have a slight interference or a slight clearance, depending on the specific combination. Transition fits can be used when a moderate amount of interference or tightness is desired while still allowing for assembly and disassembly.

  3. Interference fit: In an interference fit, the mating parts have intentional interference or overlap. The minimum size of the hole is smaller than the maximum size of the shaft, resulting in a press fit or interference fit. Interference fits provide a tight connection between parts without the need for additional fasteners. They are commonly used in applications where a secure and rigid assembly is required, such as in press-fitting bearings or gears onto shafts.

Standards. by Dan Graham

Surface finish is an important aspect of manufacturing that refers to the texture, roughness, and quality of a surface after it has been machined or processed. Measuring the surface finish is crucial in ensuring the quality and functionality of the end product. There are several methods for measuring surface finish, both contact and non-contact, which can be used depending on the type of surface and the required level of precision.

Limits and Fits

Non-Contact methods:

Laser Scanning Microscope: This is a high-resolution imaging tool that uses a laser beam to scan the surface and create a 3D image. It can measure the roughness, curvature, and texture of a surface at sub-micron resolution.

The term "limits and fits" refers to a system of standardized tolerances used to control the dimensions and fits between mating parts in mechanical assemblies. It helps ensure proper functionality, interchangeability, and compatibility of components. The system defines the acceptable variation in size between parts and specifies the allowable clearances or interferences between mating surfaces.

In limits and fits terminology, a "limit" refers to the maximum and minimum dimensions within which a part can be manufactured, and a "fit" refers to the range of clearances or interferences between mating parts. The combination of a particular limit and fit determines the type of fit between the parts.

Pins, Nuts, and fasteners

Pins by Dan Graham

What you need to know when marking out a PCD you need to know the diameter of your circle you want and the number of holes. Once you have both of these you can refer to your engineers handbook and find the measurements you need. Mark your surface with engineers blue and use a set of dividers to draw the desired circle. After this you can use a height gauge to mark the centres for you holes.

Marking PCD’s

PCD stands for pitch circle diameter and is usually measured in millimeters. It is usually used to measure the distance between the two opposite holes. If there are a certain number of holes are in a circle and divided equally then we say the diameter of the circle is pitch circle diameter.

Drilling and Reaming.

Drilling is a process of creating a hole in a material using a rotating cutting tool called a drill bit. The drill bit is pressed against the material, and as it rotates, it cuts through the material to create the hole. Drilling is commonly used for creating holes of various sizes and shapes in a wide range of materials.

Reaming is a process of enlarging and smoothing out an existing hole using a rotating cutting tool called a reamer. The reamer is inserted into the hole and rotated, removing a small amount of material at a time to achieve the desired size and finish. Reaming is commonly used to improve the accuracy, surface finish, and dimensional tolerance of an existing hole.

Parts of a drill bit

Chain Drilling

Chain drilling is the process of drilling a series of holes in a section of material that allows for slot creation.

Reaming

Reaming is a machining process used to enlarge and improve the accuracy of an existing hole. The purpose of reaming is to create a smoother, more precise hole with a specific diameter, surface finish, and alignment. Reaming is typically performed after drilling or boring operations to achieve tighter tolerances, remove any irregularities or burrs, and provide a better surface for the desired fit of a mating component.

  • The shank is the part of the drill bit that is inserted into the chuck of the drill. It is usually round or hexagonal in shape and may have a groove to help keep it securely in place.

  • The body of the drill bit is the main part that does the drilling. It is usually cylindrical or conical in shape and may have flutes or spirals that help remove the material as the bit rotates.

  • The tip is the sharp end of the drill bit that makes contact with the material being drilled. It is usually angled to help guide the bit into the material and start the drilling process.

  • The cutting edges are the sharp edges that run along the length of the body of the drill bit. They are responsible for cutting through the material being drilled.

  • The helix angle is the angle between the cutting edges and the axis of the drill bit. It affects the rate at which material is removed and the amount of torque required to turn the bit.

  • Flutes are the grooves that run along the length of the drill bit. They help to remove material from the hole as the bit rotates, which can prevent the bit from overheating and breaking.

How to change speed on a pillar drill

Reaming tools, called reamers, consist of a cutting edge, usually in the form of multiple flutes, and they are available in various shapes and sizes to accommodate different hole dimensions and requirements. During the reaming process, the reamer is rotated and fed into the existing hole, removing a small amount of material at a time. The cutting action produces a smoother finish and ensures the hole is within the specified tolerance range.

Turning and Milling

A metalworking lathe is a type of lathe specifically designed for shaping and machining metal materials. It is a versatile machine tool used in metalworking industries, workshops, and factories. Metal lathes are capable of turning and shaping metal workpieces with high precision and accuracy.

Lathes consist of a horizontally mounted spindle that holds the workpiece, which is rotated against a cutting tool. The cutting tool is fixed on a tool post that can be moved along multiple axes to perform various operations such as facing, turning, boring, threading, and grooving. The tool post can be manually operated or controlled by computer numerical control (CNC) systems for automated and programmable operations.

Lathes offer different speed settings, allowing the operator to adjust the rotational speed of the workpiece according to the material being machined and the desired cutting operation. They also come with various attachments and accessories to enhance their functionality, such as chucks, collets, steady rests, and tailstocks.

Lathes are widely used for machining cylindrical shapes, producing precision components, and creating threads on metal parts. They are essential tools in industries like manufacturing, automotive, aerospace, and metal fabrication, where precise metalwork is required.

Lathe tools

“Tool geometry”

Tool geometry plays a crucial role in lathe tools as it directly influences the cutting performance, tool life, and surface finish achieved during machining operations. Here are several reasons why tool geometry is important in lathe tools:

  • The geometry of the cutting edge, including its shape, angle, and edge preparation, determines how effectively the tool removes material from the workpiece. Proper tool geometry allows for efficient chip formation and evacuation, reducing cutting forces and power consumption.

  • The geometry of the tool affects the distribution of cutting forces and heat generated during machining. Optimal tool geometry helps to distribute these forces evenly across the cutting edge, minimizing tool wear and extending tool life. It also helps prevent issues like chipping, edge rounding, and built-up edge formation.

  • The tool geometry, including the cutting edge radius, chamfer, or nose radius, influences the surface finish of the machined part. By selecting the appropriate geometry, machinists can achieve the desired surface roughness, minimize tool marks, and reduce the need for additional finishing operations.

  • The geometry of the tool, particularly the chip breaker design, helps in controlling chip flow and breaking long chips into more manageable sizes. Effective chip control prevents chip entanglement, reduces the risk of chip clogging or jamming, and improves chip evacuation, leading to smoother machining operations.

  • Different workpiece materials require specific tool geometries to optimize cutting performance. Harder materials may require tougher tool materials and sharper cutting edges, while softer materials might benefit from larger rake angles or more robust tool geometries.

  • Tool geometry can be tailored for specific machining operations, such as roughing, finishing, threading, or grooving. Different operations may require variations in tool geometry, such as different rake angles, relief angles, or edge preparations, to achieve the best results for each specific task.

Positive rake angle

Positive rake angles promote efficient cutting and chip formation.

Advantages of positive rake angles include reduced cutting forces, lower power consumption, improved chip evacuation, and enhanced surface finish.

Positive rake angles are commonly used when machining soft materials or when aiming for high cutting speeds and productivity.

However, excessive positive rake angles can result in weaker cutting edges and increased cutting temperatures, leading to reduced tool life.

“Relief”

The relief in a lathe tool refers to the specific geometry and clearance provided to certain areas of the tool, typically behind the cutting edge. The purpose of relief in a lathe tool is to ensure proper chip evacuation, reduce friction and cutting forces, prevent tool rubbing, and improve the overall cutting performance.

When a lathe tool lacks relief, it can come into contact with the machined surface or the workpiece material during cutting. This rubbing or dragging of the tool against the workpiece can cause tool wear, poor surface finish, and even chatter vibrations. Relief angles prevent such rubbing, allowing for smoother and more stable cutting.

Screw cutting

Cutting threads on a lathe can sound complicated but when taken step by step it becomes a straightforward operation.

  • Choose a cutting tool suitable for the material you're working with and the desired thread size and pitch. It should have the correct shape and angle for cutting threads.

  • Securely mount the workpiece in the lathe's chuck or collet. Make sure it is centered and aligned with the lathe's axis. Adjust the lathe's speed and feed settings according to the material and thread specifications. Align the cutting tool with the chosen datum edge

  • Now that you are happy with the setup of your tool and the job in your holding devices. you can set the depth you’d like to cut on each pass and engage the clutch leaver to turn the spindle on.

Cutting speeds vs Feed Rate

In machining processes, such as milling or turning, cutting speed and feed rate are two important parameters that affect how material is removed from a workpiece. Here's a simple explanation of the difference between cutting speed and feed rate:

A milling machine is a machine tool used to remove material from a workpiece by feeding it against a rotating milling cutter. It is a versatile machining tool capable of performing a wide range of operations such as milling, drilling, boring, and threading.

Milling machines consist of a cutting tool, known as a milling cutter, which rotates at high speed and removes material from the workpiece. The workpiece is typically secured on a worktable or a workholding device that can be moved in multiple directions, allowing the milling cutter to remove material from various angles and create complex shapes.

Milling machines can be manually operated or equipped with computer numerical control (CNC) systems for automated and precise machining. CNC milling machines are programmable, allowing complex shapes and patterns to be created with high accuracy and repeatability.

Milling machines are widely used in industries such as manufacturing, metalworking, aerospace, and automotive. They are capable of producing a wide range of components, from simple flat surfaces to intricate three-dimensional shapes. Milling machines are essential tools for prototyping, production machining, and precision engineering tasks.

Milling tools

“Rake angle”

The rake angle in lathe tools is an essential parameter that determines the cutting performance and tool life during machining operations. It refers to the angle formed between the cutting edge of the tool and a reference plane

Negative rake angle

Negative rake angles are less common and typically used for specific machining applications.

The advantages of negative rake angles include increased tool strength and durability, especially when machining hard or tough materials.

Negative rake angles can generate higher cutting forces and require more power for machining.

They may also produce shorter and thicker chips, which can be advantageous in certain circumstances, such as when dealing with stringy or ductile materials.

In this diagram, we would use the rotation of the slot drill as cutting speed in relation to the movement of the material. How fast the cutting edge removes the material.

Feed rate relates to how fast the tool is moving through the material. so how much surface is covered by the tool.

  • The half-nut is a mechanism that engages with the lead screw, allowing the carriage to move longitudinally along the lathe's bed. Engage the half-nut by hand when the cutting tool is positioned at the starting point of the thread.

  • Maintain a constant speed and feed rate while cutting the threads. Use cutting fluid or lubricant to improve tool life and reduce friction. Ensure that the tool is properly aligned and making clean, accurate cuts.

  • Once the cutting process reaches the desired thread length, disengage the half-nut and stop the lathe. Allow the spindle to come to a complete stop move your tool away from the job only on the x-axis and reverse the feed. Once you have cleared the front of the job, set your next depth and keep this process going until you have a cleanly cut thread. this may take several passes

Cutting Speed: Cutting speed refers to the speed at which the cutting tool or workpiece moves relative to each other during the machining process. It is usually measured in surface feet per minute (SFPM) or meters per minute (m/min). Cutting speed determines how fast the material is removed by the cutting tool. Higher cutting speeds result in faster material removal.

Feed Rate: Feed rate, on the other hand, refers to the speed at which the cutting tool moves through the workpiece during the machining process. It is usually measured in inches per minute (IPM) or millimeters per minute (mm/min). The feed rate determines how much material is removed in a single pass of the cutting tool. Higher feed rates result in a greater amount of material being removed.