How to Make a Thread Tap
![How to make a Thread Tap - How to easily tap a thread - DIY Thread Tap - Putting a tread into metal.](/proxy/?url=https://content.instructables.com/FQI/YNTI/KF141088/FQIYNTIKF141088.jpg&filename=How to make a Thread Tap - How to easily tap a thread - DIY Thread Tap - Putting a tread into metal.)
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
![How to make a thread tap. DIY tapping a thread (1).jpg](/proxy/?url=https://content.instructables.com/F70/XX9Z/KF14108Q/F70XX9ZKF14108Q.jpg&filename=How to make a thread tap. DIY tapping a thread (1).jpg)
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.
![How to make a thread tap. DIY tapping a thread (4).jpg](/proxy/?url=https://content.instructables.com/FRU/8SHL/KF14108T/FRU8SHLKF14108T.jpg&filename=How to make a thread tap. DIY tapping a thread (4).jpg)
We take an existing bolt of the exact thread diameter and pitch required.
![How to make a thread tap. DIY tapping a thread (5).jpg](/proxy/?url=https://content.instructables.com/FE2/OJRI/KF14108U/FE2OJRIKF14108U.jpg&filename=How to make a thread tap. DIY tapping a thread (5).jpg)
I recommend a high tensile steel bolt. But mild steel may work as well.
![How to make a thread tap. DIY tapping a thread (6).jpg](/proxy/?url=https://content.instructables.com/FKC/J2CO/KF14108V/FKCJ2COKF14108V.jpg&filename=How to make a thread tap. DIY tapping a thread (6).jpg)
The idea is to make cuts along the bolt threads so that it somewhat resembles an actual thread tap.
![How to make a thread tap. DIY tapping a thread (7).jpg](/proxy/?url=https://content.instructables.com/FT6/PEXR/KF14108X/FT6PEXRKF14108X.jpg&filename=How to make a thread tap. DIY tapping a thread (7).jpg)
Secure the bolt in a vice
![How to make a thread tap. DIY tapping a thread (8).jpg](/proxy/?url=https://content.instructables.com/FR0/VH4I/KF14108Z/FR0VH4IKF14108Z.jpg&filename=How to make a thread tap. DIY tapping a thread (8).jpg)
Carefully cut the slots with a thin cutting disk.
![How to make a thread tap. DIY tapping a thread (9).jpg](/proxy/?url=https://content.instructables.com/FUG/8311/KF141090/FUG8311KF141090.jpg&filename=How to make a thread tap. DIY tapping a thread (9).jpg)
Your angle grinder cuts should look something like this.
![How to make a thread tap. DIY tapping a thread (10).jpg](/proxy/?url=https://content.instructables.com/FWM/I3R3/KF141091/FWMI3R3KF141091.jpg&filename=How to make a thread tap. DIY tapping a thread (10).jpg)
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.
![How to make a thread tap. DIY tapping a thread (11).jpg](/proxy/?url=https://content.instructables.com/F2D/2809/KF141092/F2D2809KF141092.jpg&filename=How to make a thread tap. DIY tapping a thread (11).jpg)
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.
![How to make a thread tap. DIY tapping a thread (12).jpg](/proxy/?url=https://content.instructables.com/FHP/H815/KF141094/FHPH815KF141094.jpg&filename=How to make a thread tap. DIY tapping a thread (12).jpg)
Then quench till it is a safe temperature to touch.
![How to make a thread tap. DIY tapping a thread (13).jpg](/proxy/?url=https://content.instructables.com/FCN/YPHV/KF141095/FCNYPHVKF141095.jpg&filename=How to make a thread tap. DIY tapping a thread (13).jpg)
The bolt is now hard and somewhat brittle.
![How to make a thread tap. DIY tapping a thread (14).jpg](/proxy/?url=https://content.instructables.com/FO6/LWKR/KF141096/FO6LWKRKF141096.jpg&filename=How to make a thread tap. DIY tapping a thread (14).jpg)
Now to test it.
Drill the required size hole in the piece that needs tapping and add some oil.
![How to make a thread tap. DIY tapping a thread (15).jpg](/proxy/?url=https://content.instructables.com/FBJ/6D5I/KF141097/FBJ6D5IKF141097.jpg&filename=How to make a thread tap. DIY tapping a thread (15).jpg)
Start tapping the thread.
![How to make a thread tap. DIY tapping a thread (16).jpg](/proxy/?url=https://content.instructables.com/FJH/OGLQ/KF141098/FJHOGLQKF141098.jpg&filename=How to make a thread tap. DIY tapping a thread (16).jpg)
There you have it.
This quick tool was able to cut a pretty decent thread in 10mm 3/8 inch mild steel.
![How to make a thread tap. DIY tapping a thread (17).jpg](/proxy/?url=https://content.instructables.com/FEO/M2VG/KF141099/FEOM2VGKF141099.jpg&filename=How to make a thread tap. DIY tapping a thread (17).jpg)
This would be a good enough substitute in some situations.
![How to make a thread tap. DIY tapping a thread (18).jpg](/proxy/?url=https://content.instructables.com/F00/CVBL/KF14109A/F00CVBLKF14109A.jpg&filename=How to make a thread tap. DIY tapping a thread (18).jpg)
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