Taps Cutting or Forming

[mototraxtech]

I was just curious. I see that forming taps are becoming more available and less expensive. Some the the pros of these taps are stronger threads and longer life. Claimed to be 2 to 20 times as long as normal taps. They are getting really close in cost to cutting taps. Another advantage I have seen is not chips which mean blind hole = no problems.


What are others thoughts on the two.

 

[65535]

Forming taps take a LOT of force to go through harder materials and in some thinner materials can crack the part.

It's a per application choice.

 

[mototraxtech]

hmm good point!

 

[precisionworks]

The Balax website has some of the best information on both cutters & formers: http://www.balax.com/catalog.pdf

Be sure to read pages 53 & 54 on pre tap hole sizing. Formers take a different hole size than cutters, and will break in a heartbeat if the hole size is not dead on.

Balax says this,"If you see a stringy chip while machining, then the material is an excellent Thredfloer candidate. If you see a very fine powdery chip, then the metal may be too brittle to be cold formed."

Page 67 shows a long list of materials that can be readily form tapped. Nickel alloys, Ti alloys, Stainless types 300 & 400, etc. are all included. Tapping torque is higher, as there is greater contact between the tap & the work - some metal is being displaced outward (away from the tap) while an equal amount of metal is being forced inward. Correct coating, lubrication, and speed are all important.