How to Sharpen Metal Lathe Tools

What You'll Need
Eye protection
Bench grinder
Rubber gloves
Dry cloth
Diamond sharpening tool

To sharpen your metal lathe tools in a safe and effective manner, use the following guidelines that have been presented in an easy-to-understand manner.

Step 1—Getting Started with Basic Preparations

Get started by wearing proper eye protection. Small fragments of metal are dispersed in the air when using the lathe. Similarly, wearing protection gloves is also important. You need to ensure that the bench grinder is totally still before you begin the sharpening. For this, set-up the tool support in the proper manner. Attach the bench grinder upon the work bench using clamps.

Step 2—Dress the Grinding Wheel

A grinding wheel is the main tool used for sharpening lathe tools. You need to dress the grinding wheel. This essentially refers to a process of preparing the grinding wheel. This is because the grinding wheel develops a small build-up that can affect its performance, i.e. its sharpening capability. It is usually recommended that when using the bench grinder, a diamond sharpening tool is the best choice for dressing the wheel. Using the diamond-sharpening tool, repeatedly rub the grinding wheel’s outer edges to remove the debris and sharpen it.

Step 3—Ensuring Proper Angles

Understand that different lathe tools tend to have different angles at which they cut. Many of the cutting edges are between 7 and 30 degrees. Even the sharpest of lathe tool tips don’t have cutting angles exceeding 90 degrees, as this will cause increased scraping of the work piece. It is recommended not to tamper with these angles, maintaining the original edge is the safest option.

Step 4—Ensuring Proper Contact

You should also place the lathe tool on its dedicated rest and advance it gently. Do this until the tool makes contact with the wheel. Ensure that the blade is not pressing against the wheel—it should have minimal contact with the wheel. If the angle is not right or you are pressing hard upon the lathe tool, chances are that the blade will bounce or will develop excessive vibrations, weakening your grip over it.

Step 5—First Phase of Sharpening Lathe Tools

Push the lathe tool slightly against the grinding wheel. Ensure that you limit contact of the lathe tool with the wheel for about 10 seconds. You should be able to see some sparks emerging during this short interval if the angle and level of contact is proper. Try to move the lathe tool from side-to-side in a gentle manner while sharpening it. Keep checking the pattern in which the sparks burst. They should be visible along the entire edge of the tool. Keep moving and adjusting the lathe tool to ensure that sparks are produced along its entire cutting edge.

Step 6—Second Phase of Sharpening Lathe Tools

Repeat the 10-second sharpening bouts a few times. When it seems that the lathe tool is sharp enough, dip it in a bowl of water. This cooling is vital. The tool can get too hot due to heating caused by extreme friction. Cooling ensures that you can continue to hold the tool during the remainder of the sharpening process. Now, repeat the same process with the other side of the lathe tool. Ensure that the surface is dry before proceeding. You can wipe the lathe tool with a dry cloth for this. Ensure that you don’t over-grind any side of the lathe tool as this creates the risk of making the tool tip weak and prone to getting cracked.