Taps and dies

[Anonymous]

I buy the odd tap from 'Tap & Die', mostly ME sizes. For standard threads I use 'Drill-Service', or my local tool emporium, who stocks OSG and Dormer. I do a lot of machine tapping, so I often buy spiral point and spiral flute taps, always in HSS.

I don't worry about being able to soften taps, because I don't break them. I use a thread depth of 60-70%, for most threads, and normal materials, you don't need more. The last tap I broke, some years ago, came from Tracy Tools, and it chipped a tooth rather than breaking the tap proper. I've never bought from them since.

As far as I know most HSS tool steels have a hardness in the range of 60-68Rc. If we take M2, for instance, which is often used for taps The maximum hardness is listed as about 66Rc. For silver steel the maximum hardness is listed as 65-69Rc. So for all practical purposes there doesn't seem to be much difference between the hardness of silver steel and HSS.

Regards,

Andrew

[Bill PudneyParticipant @billpudney37759]

I too use Drill Service, for all sorts of small things. Their service and quality is good and their prices reasonable. They can even get small sizes of gauge plate to Australia cheaper than it's available locally, it is very expensive locally! Clearly no connection other than as a satisfied customer.

cheers

Bill

[HopperParticipant @hopper]

Posted by John Stevenson on 23/06/2013 21:45:09:

Ironacally only the tap and die company use what they call HQS.

High Quality Steel?? (Almost looks like HSS too!)

[Mike PooleParticipant @mikepoole82104]

The great thing about HSS was that it would hold its temper at red heat, not a situation a tap is likely to encounter. Carbon steel has alot of fans for taking a keener edge than HSS. Taps made from HSS are usually ground after hardening which makes a high quality tap. I do not think HSS is any tougher than properly hardened and tempered carbon steel. What do the metalurgists think?

Mike

[OssieParticipant @ossie]

Thanks for all the great response folks it was. Great help

Dave.

[Author]

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