Drill shank hardness

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tornitore45
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Drill shank hardness

Post by tornitore45 » Mon May 20, 2019 9:10 am

I was watching a guy on Utube making late tools from the shank of HSS broken drill bits.
I pointed out the the shank is not hardened.
He responded that in his case it is because he uses HS Conbalt.

That makes no sense since an alloy element added to improve the business end of a drill has no bearing on the necessity of having a softer shank to assure a good grip.

Is Co HSS drill shank hardened? Or he thinks that just because is Co is much harder.
Mauro Gaetano
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SteveHGraham
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Re: Drill shank hardness

Post by SteveHGraham » Mon May 20, 2019 9:27 am

I have spun them, and it left marks, and I have filed the burrs off, so I think they are soft.
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tornitore45
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Re: Drill shank hardness

Post by tornitore45 » Mon May 20, 2019 10:26 am

Well, I saw it on the internet so it must be true. Yea.
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Conrad_R_Hoffman
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Re: Drill shank hardness

Post by Conrad_R_Hoffman » Mon May 20, 2019 10:37 am

I've never seen an HSS drill bit with a hard shank, cobalt included. If making something else, like a cutting tool, you can fix that with a torch and bucket of water.
Conrad

1947 Logan 211 Lathe, Grizzly G1006 mill/drill, Clausing DP,
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SteveM
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Re: Drill shank hardness

Post by SteveM » Mon May 20, 2019 10:51 am

tornitore45 wrote:
Mon May 20, 2019 10:26 am
Well, I saw it on the internet so it must be true. Yea.
Yes, I saw that both Shakespeare and Abraham Lincoln said so.

Yes, they are not sharpened.

If you spin a burr on one and it won't go into the index, you can chuck it in the lathe and turn the burr off, rather than trying to file or stone it.

Steve

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tornitore45
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Re: Drill shank hardness

Post by tornitore45 » Mon May 20, 2019 11:01 am

you can fix that with a torch and bucket of water.
Not HSS. Hardening HSS is a not a process available at the typical Home Shop Guy.
I make cutting tool from broken HSS bit but the only useful part is the web which basically limit the design to small grooving tool.
Mauro Gaetano
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Frank Ford
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Re: Drill shank hardness

Post by Frank Ford » Mon May 20, 2019 11:23 am

Unlike drill bits, end mills have hardened shanks, so I save 'em and make various tools by grinding. An angle grinder, die grinder, Dremel or Foredom with appropriate cutoff discs make quick work of cutting them to length, etc.
Cheers,

Frank Ford

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tornitore45
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Re: Drill shank hardness

Post by tornitore45 » Mon May 20, 2019 12:13 pm

Same here. I save any hard tool steel. Tap and even dies, I made a form tool out of a broken scissor blade. Too thin to be used flat but supported with a blank worked fine.
Mauro Gaetano
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warmstrong1955
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Re: Drill shank hardness

Post by warmstrong1955 » Mon May 20, 2019 12:28 pm

Drill shanks make good pin punches for roll pins. I've made a bunch of 'em with old ones I saved.
Easy enough to machine a tip on, and hard enough not to mushroom, and not to brittle to fling little shards at you. Hold up better than 4140 Q&T.

I posted these before. Made these for a friend. The store bought models are wildly expensive.
100_3004.jpg
100_3012.jpg
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Re: Drill shank hardness

Post by spro » Mon May 20, 2019 12:37 pm

I agree in many ways. The shanks and part of the flutes are reusable. Frank got it right about end mills. I've never had one spin to damage the shank.

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Re: Drill shank hardness

Post by spro » Mon May 20, 2019 12:47 pm

Warmstrong. I probably commented on these already but it is worth knowing again. The way the ends are ground, they encapsulated the roll pin while driving it out. It is shrinking the diameter of the pin. It ain't no gasket punch.

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Re: Drill shank hardness

Post by Conrad_R_Hoffman » Mon May 20, 2019 2:46 pm

tornitore45 wrote:
Mon May 20, 2019 11:01 am
you can fix that with a torch and bucket of water.
Not HSS. Hardening HSS is a not a process available at the typical Home Shop Guy.
I make cutting tool from broken HSS bit but the only useful part is the web which basically limit the design to small grooving tool.
Opps! You're right. Probably only works with HF drills.
Conrad

1947 Logan 211 Lathe, Grizzly G1006 mill/drill, Clausing DP,
Boyar-Schultz 612H surface grinder, Sunnen hone, import
bandsaw, lots of measurement stuff, cutters, clutter & stuff.


"May the root sum of the squares of the Forces be with you."

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