Introduction: How to Make a Thread Tap
How to make a quick and easy tap for cutting a thread.
Supplies
- High tensile steel bolt
- Angle grinder (with cutting disk)
- Bench vice
- Butane torch
- Tin can (for quenching)
- Adjustable wrench
Step 1:
This tool is more of a last resort when you need to tap a thread
and you do not have immediate access to the actual necessary tool.
Step 2:
We take an existing bolt of the exact thread diameter and pitch required.
Step 3:
I recommend a high tensile steel bolt. But mild steel may work as well.
Step 4:
The idea is to make cuts along the bolt threads so that it somewhat resembles an actual thread tap.
Step 5:
Secure the bolt in a vice
Step 6:
Carefully cut the slots with a thin cutting disk.
Step 7:
Your angle grinder cuts should look something like this.
Step 8:
Make yourself a quenching bath, I am using a mixture of salt water.
But I have used old engine oil in the past.
Fire up your burner.
Step 9:
Heat the bolt to approximately 800 degrees Celsius,
or 1450 to 1500 degrees Fahrenheit. Which is expressed as a bright cherry red colour in carbon steel.
Step 10:
Then quench till it is a safe temperature to touch.
Step 11:
The bolt is now hard and somewhat brittle.
Step 12:
Now to test it.
Drill the required size hole in the piece that needs tapping and add some oil.
Step 13:
Start tapping the thread.
Step 14:
There you have it.
This quick tool was able to cut a pretty decent thread in 10mm 3/8 inch mild steel.
Step 15:
This would be a good enough substitute in some situations.
Step 16:
