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8-32 tap in O1 tool steel hardened to 60RC

cstrickland

Aluminum
Joined
Mar 31, 2011
Location
ohio
Ok so we have a piece of O1 tool steel that we typically drill and tap several #8-32 holes in prior to hardening to 60-62 RC (these are through holes not blind) . well it seem two holes got over looked before the hardening. looking for recommendations for a tap that will allow us to tap the last two 8-32 thread as the part sits at 60Rc

We have looked at carbide, but at that size trying to hand or machine tap 60RC there is concern the tap will break.

Have also thought or threadmill , but it is not recommended on this size hole & material hardness due to deflection.


anybody with first hand experience able to make a tap recommendation make, coating , flute configuration etc !!

Charles
 
We do 6x32 in hardened material about 6 passes


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yeah we have been kicking this around as our next step. What thread mill were you using do you remember ?/ I am looking at a Harvey tool model single flute for hardened steel.
 
yeah we have been kicking this around as our next step. What thread mill were you using do you remember ?/ I am looking at a Harvey tool model single flute for hardened steel.

Call Harvey tool tech support.they will save you a bunch of headaches.
When I had some issues they were prompt about getting back to me..
 
When you say 'two holes got overlooked' do you mean they did not get tapped, or did not get drilled either?

If holes not drilled, EDM cost for each hole will be in the $50 range. If you can make a new part for $100 then throw the one you have away.
 
we used to tap 10-32's in hardened 8620, try a OSG EXO VC-11, they are quite amazing. Emuge makes some bad ass taps for hardened material. Stay away from carbide, as you guessed it'll just snap.
 
We tried the 40.00 Emuge taps wouldn’t tap the slide of a colt gold cup stainless. We threadmill those only


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I would check out Carmex Tool. They are a company built around threading and have a line of thread mills designed for up to 62RC. They go all the way down to 0-80 so they got you covered. Would be nice too to have feeds and speeds to go off that are proven for what you are doing. They make great stuff of what I've used from them.
 
I would check out Carmex Tool. They are a company built around threading and have a line of thread mills designed for up to 62RC. They go all the way down to 0-80 so they got you covered. Would be nice too to have feeds and speeds to go off that are proven for what you are doing. They make great stuff of what I've used from them.

Do you know someone that sells Carmex??

I would like to know more....... :skep:
 
MSC carries their product. I spoke with them at IMTS 2016 and 18 but I've just pulled tools I need from their book and bought them there.
 
Carmex are local for me. Fantastic product line, but not cheap. We would call them to get part numbers and then order through DXPe or MSC.

That said I've got one of the Harvey multi-thread profile tools for hardened steel in my machine right now. We'll see how it goes. Nothing near as hard as what you're doing.
 
Tapping hole in hardened tool steel

Ok so we have a piece of O1 tool steel that we typically drill and tap several #8-32 holes in prior to hardening to 60-62 RC (these are through holes not blind) . well it seem two holes got over looked before the hardening. looking for recommendations for a tap that will allow us to tap the last two 8-32 thread as the part sits at 60Rc

We have looked at carbide, but at that size trying to hand or machine tap 60RC there is concern the tap will break.

Have also thought or threadmill , but it is not recommended on this size hole & material hardness due to deflection.


anybody with first hand experience able to make a tap recommendation make, coating , flute configuration etc !!

Charles

Have you considered annealing the block and then tap the holes and reharden the block or make the part over? Any other way may be cost prohibitive.

Roger
 
Before you sink a lot of money in tooling, you have to consider if you will need it in the future. Sounds like this may be a one time screw up. It may be more cost effective to anneal and then harden again.
 








 
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