• Check that the line center is running true. If it is not running true, remove the center, clean all surfaces, and replace the center. Check again for trueness.

Workhardening rate

Figure A:depicts a standard turning tool to create a semi-square shoulder. If there is enough material behind the cutting edge, the tool can also be used for roughing.

Scenario: You are designing a new type of metal wrench for a construction company. The wrench needs to be strong enough to handle heavy torque, but also flexible enough to avoid breaking under extreme pressure.

There are many different tools that can be used for turning, facing, and parting operations on the lathe. Each tool is usually composed of carbide as a base material, but can include other compounds. This section covers the different appearances and uses of lathe cutting tools.

Workhardening examples

The lathe is a very versatile and important machine to know how to operate. This machine rotates a cylindrical object against a tool that the individual controls. The lathe is the forerunner of all machine tools. The work is held and rotated on its axis while the cutting tool is advanced along the line of a desired cut. The lathe is one of the most versatile machine tools used in industry. With suitable attachments, the lather may be used for turning, tapering, form turning, screw cutting, facing, dulling, boring, spinning, grinding, polishing operation. Cutting operations are performed with a cutting tool fed either parallel or at right angles to the axis of the work. The cutting tool may also be fed at an angle, relative to the axis of the work, for machining taper and angles. On a lathe, the tailstock does not rotate. Instead, the spindle that holds the stock rotates. Collets, centers, three jaw chucks, and other work-holding attachments can all be held in spindle. The tailstock can hold tools for drilling, threading, reaming, or cutting tapers. Additionally, it can support the end of the workpiece using a center and can be adjusted to adapt to different workpiece lengths.

Figure C:nose has a very large radius, which helps with fine finishes on both light and heavy cuts. The tool can also be used to form a corner radius.

6. When installing and removing chucks, face plates, and centers, always be sure all mating surfaces are clean and free from burrs.

How doesworkhardening increase strength

Figure G:depicts a grooving or under-cutting tool. As shown, it is used to cut grooves into the workpiece. When there are proper clearances, the tool can cut deeply, or cut to the left or right.

Manufacturing Processes 4-5 Copyright © by LamNgeun Virasak is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

It is crucial to understand the trade-offs inherent in work hardening. While it provides enhanced strength, it also increases brittleness. Choosing the right material, applying appropriate deformation techniques, and using controlled annealing processes are key to harnessing the benefits of work hardening while mitigating its drawbacks.

As always we should be aware of safety requirements and attempt to observe safety rules in order to eliminate serious injury to ourselves or others.

22. Make sure the machine is turned off and clean before leaving the workspace. Always remove the chuck wrench after use, avoid horseplay, keep floor area clean. Use care when cleaning the lathe, the cutting tools are sharp, the chips are sharp, and the workpiece may be sharp.

Tailstock Center 1. Reference the center of the tailstock when setting the tool. 2. Position the tip of the tool with the tailstock center. UNIT TEST 1. Please list the ten most important parts of the Lathe. 2. Please list five Lathe safety guidelines. 3. Why is cutting speed important? 4. What is a Toolholder? 5. Where do you mount a Toolholder? 6. How far do you extend the cutting tool in the Toolholder? 7. Please list three different cutting tools. 8. Please describe the positioning of the tool. 9. Explain how to center the workpiece. 10. What are the two way to center the workpiece?

Workhardening meaning

Figure H:depicts a parting tool. Parting tools cut off the stock at a certain length. This tool requires a preformed blade and holder.

Wear glasses, short sleeves, no tie, no rings, no trying to stop the work by hand. Stop the machine before trying to check the work. Don’t know how it works? –“Don’t run it.” Don’t use rags when the machine is running.

Figure F:depicts a facing tool. This cutter is used to face the end of a workpiece to provide for a smooth, flat finish. If the stock has a hole in the center, utilize a half-center to stabilize and support the workpiece.

Strain hardening

**1. Applying Work Hardening:** The wrench could be work hardened by processes like cold hammering or rolling. These would increase the material's strength and resistance to wear. **2. Benefits and Drawbacks:** * **Benefits:** Work hardening would increase the wrench's strength and durability, allowing it to handle high torque. * **Drawbacks:** The increased brittleness due to work hardening could lead to the wrench cracking or fracturing under extreme pressure, potentially leading to injury. **3. Mitigation:** To mitigate the increased brittleness, the wrench could be partially annealed after work hardening. This would reduce internal stress and restore some of the metal's ductility. The annealing process should be carefully controlled to achieve the desired balance between strength and flexibility.

1. Remove the chuck key from the chuck immediately after use. Do not turn the lathe on if the chuck is still in the chuck key.

When set too high the tool breaks down quickly, time is lost replacing or reconditioning the tool. Too low of a CS results in low production.

16. Make sure that the tailstock is locked in place and that the proper adjustments are made if the work is being turned between centers.

What causesworkhardening

a) The metal's atoms becoming more loosely packed. b) The formation of new, weaker grain boundaries. c) Internal stress created within the metal. d) The metal's surface becoming smoother.

To reposition the cutting tool, move the cross slide and lathe saddle by hand. Power feeds are also available. Exact procedures are dependent on the machine. The compound provides a third axis of motion, and its angle can be altered to cut tapers at any angle.

Figure D:depicts a rotated standard turning tool. Its nose leads the cutting edge to create light finishing cuts on the outside diameter and face of the shoulder.

a) To increase the metal's strength. b) To further harden the metal. c) To reduce the metal's brittleness. d) To increase the metal's conductivity.

By understanding the intricacies of work hardening, engineers and metallurgists can leverage its advantages to create stronger, more durable metal components, while ensuring their safe and reliable operation.

Workhardening process

5. Place the tool post holder to the left of the compound slide. This will ensure that the compound slide will not run into the spindle or chuck attachments.

Workhardening vs strain hardening

Notice the Feedrate for roughing cuts range from .005 to .020 depending on the material being machined, and .002 to .004 for the finish feed for the different materials.

Figure B:depicts a standard turning tool with a lead angle. This angle enables for heavy roughing cuts. Ititalso possible to turn the tool to create a semi-square shoulder.

Notice the largest roughing cuts range from .010 to .030 depending on the material being machined, and .002 to .012 for the finish feed for the different materials.

Work hardening, also known as strain hardening, is a fascinating phenomenon in metallurgy where a metal's strength and hardness increase with repeated applications of stress, often through bending, hammering, or rolling. While this sounds beneficial, it comes with a significant drawback – increased brittleness. This makes work hardening a double-edged sword, offering increased strength but at the cost of reduced ductility.

• Place the end of the workpiece in the chuck and slide the tailstock up until it supports the other end of the workpiece.

Imagine a metal lattice – a regular arrangement of atoms. When stress is applied, these atoms shift and deform, disrupting their original arrangement. This creates a more tightly packed structure, leading to increased resistance to further deformation, hence the increase in hardness.

However, this tight packing also creates internal stress within the metal. This trapped energy makes the metal more susceptible to cracking and fracturing under stress, leading to increased brittleness.

7. If more accuracy is needed when positioning the saddle, use a dial indicator that is attached to the saddle. Dial indicators press against stops.

a) Decreased strength and increased ductility. b) Increased strength and decreased ductility. c) No change in strength or ductility. d) Increased ductility and decreased strength.