They form the thread rather than cutting it. Commonly used on softer materials.

Russell.

Hi Richard

If you decide to try them, they use a different tapping drill size… As they do not remove metal the hole will be bigger than for a cut tap. to allow for the metal pushed up by the swaging. If they are marked check the manufacturers site. They work well on thinner sheet.

Regards
John

Yes they are thread forming taps,they require larger tapping holes ,ie about 65% thread ,the threads are stronger due to the forming action,

Advantages virtually no swarf,less tap breakage ,high operating speed ,ideal for cnc work particularly with electronic solid tapping with pitch control,reduced cnc machine downtime and very few scrapped castings. needs high performance soluble oil with regular control of lubricant strength.

No good for any other work,they are a high speed production tool

.

I disagree with that statement. I have to tap some 3mm holes in drawn aluminium bronze and this stuff is so grabby it ought to be in politics. With normal taps you hear the squeal 1.3453765 seconds after the tap breaks.

Using fluteless taps stops all that and tap life is up by 3,000 % as a broken tap is useless.