The ability to cut threads in wood can be useful for many projects. Often the needed tap can be expensive and a car ride away. For many applications, a tap can be made from a spare bolt. This simple tap can be made in less than 5 minutes with amazing results.
Step 1: Tools and Materials
- Angle Grinder
- Bench Grinder
- Bolt or screw the size of the desired threads
Step 2: Shape Tap
If using a bolt, cut off the hex head. Create a slight taper on one end of the thread using a bench grinder. You can rotate it by hand or by using a drill to ensure an even taper. This will center your tap when using it.
Step 3: Clamp Tap and Cut Flutes
Clamp your tap on a work bench or in a vice and cut 3 or 4 flutes along the tap. This will give somewhere for the wood chips being cut from your threads to go.
Step 4: Clean Up Threads
Using a nut, run it up and down your tap. This will clean up any burs developed from cutting the flutes.
Chuck the tap in a drill and verify that it runs true. I haven't noticed any damage to my chuck from clamping directly on the threads. If you are concerned about possible damage, grind the threads away with a bench grinder.
Step 5: Tap Hole
Drill a clearance hole just smaller than the minor diameter of the threads. When tapping the hole go slowly and back out after every other revolution or so to clear out the wood chips. These threads will not be as strong as a threaded insert or a t-nut, but they are very useful for some applications.
What other shop tricks do you have up your sleeve? Let me know in the comments.