Heat treating M2 HSS..the wrong way?

[Kozzy]

In an auction buy a few years ago, I got about 60 lbs of HSS (M2) drill blanks as just an aside in a box with something else I was bidding on.  They've been handy when I need a ground bar or pin but I haven't actually "made" something of any of them.  They're typically in the 3/8" dia range with some larger and smaller.

Reading up on heat treat of M2, it's kind of a pain to do..that is if you do it right.  What I'm asking about is doing it wrong--the simplistic no brainer way.  I'm not looking for perfection, just "serviceable" for simple tooling like the oddball punch or small chisel type thing here and there.

Before I experiment re-inventing the wheel, I was wondering if anyone had done a Q&D HT on M2 with reasonable results--Something like a heat to the magnetic transition plus, oil quench, and temper more in the 400 F range than the 525+ that they say to use  to get the best from it.  I'm not looking for superior, just reasonably usable.  Since I have the blanks already,I'd like to get some good from them but not if it's going to be a hassle.  If the results from a no-brainer HT are likely poor, I'll just save them to use as they are--they make nice drive pins and such.

Any suggestions from your experiments on M2?  Some aspect of the HT process on M2 I can't short-cut without problems?  Do I need to get to that ultra hot 2200f to get anywhere with a HT and is a lower temp draw (my oven doesn't like 500+) going to give me crumbles rather than tooling?

Again, not trying to end up with superior stuff, just serviceable from the stock I already have sitting around.   Better to learn from the experienced and cut my failure rate a bit before I begin playing around to see for myself.

Thanks

[ThomasPowers]

If you don't need the special properties of a HSS; trying to use it for "lesser" things is rather like heating your metal by burning dollar bills.  Yes you can do it but it's a waste!

I'd suggest selling it off at a blacksmith conference and replacing it with a steel more suited to your purposes and heat treating methods.

[Judson Yaggy]

Master T, could you expand your answer some?  Why is it a waste?  Probably not just because you say so, there might be good literature out there, but I've seen very little written on Kozzy's exact question.   I'm particularly interested because my shop seems to be a net importer of HSS from Iron In the Hat (despite not remembering that I put a ticket in whatever cup got me that pile of HSS).   I for one would be interested in the de-rated heat treatment of HSS.  

Is experimentation really equivalent to burning dollar bills?

[ThomasPowers]

For some of the more extreme alloys you really do need the high tech heat treat to get the utmost out of them,  Doing an improvised heat treat you are not going to get what the extra money invested in the alloy can give you---shoot you may end up with a worse tool than making the same out of free coil spring that you can do an appropriate heat treat on.  It of course belongs to the owner; but what would your feelings be if he said he wanted to chop up a mint condition anvil to make paperweights from it? I strongly suggest he saves it until he has access to the fancy heat treat or trade it for an alloy that will work easier and heat treat better.

[ianinsa]

Just a thought here , is there a business near you that uses M2'properly? Then you can ask them to trade? Ie. You give them some of your blanks and they  properly heat treat some of your 'homemade ' tools? That way you get the right thing at virtually no cost.

[Crazy Ivan]

For M2, you really want capability to ramp and soak your piece. It's not a very tough steel however so I would just use some coil spring for punches and tools before using m2. I understand that you want to use it since you have it however so I would suggest you try to do the heat treat and temper in one step by running the temper off residual heat or from a hot bar. M2 requires a minimum 2 hour temper though so Im not sure how that may work out. Again, your time may be better spent using a more common alloy you are comfortable with and within your shops capabilities. Let us know how anything turns out if you try something. 

[Gergely]

Hi Kozzy,

I have a very little experience in this area, because - just as you are about to - I was curious about forging some pieces of HSS I found. So here it is:

First I had a piece of T1 HSS steel, it was really hard to forge by hand (3/4 square stock), I shaped it into a cold cut chisel. Heat treated it by scientific exactness  : normalized at orange heat then air cooling it (wrong way), then heated to almost white and quenched to oil, tempered it back to purple-blue by residual heat. This piece has become the simple best cold cut I ever made. I've used it for two years without resharpening.

Second time I made a side chisel. I thought I did everything as the first time, but the result was different. It works but doesn't hold its edge like the other.

The last time with T1 I made a hot slot punch. No heat treat (I mean only normalized) and it's a superior tool. Works at red heat as it was cold.

I forged M2 once. I did it under power hammer which helped a lot. This was in the recent past when I already knew that HSS airhardens too. So I did not do any further HT as to heat it to orange and let it cool in the air. It became a usable pointer punch which I use for knocking out bike chain pins. Not much for testing though...

If I helped with my rant: I'm glad, if I'm not: sorry for wasting your time. 

Bests

Gergely

[Kozzy]

Thanks for the suggestions.  I'll monkey with a couple of the blanks just because they are "there"..no loss if it's a failure.  I got my money's worth many times over with that auction lot--a few thousand dollars of brand new drill bits at a hundred bucks.  Several hundred were smaller solid carbide bits and they've saved my hind end many times over, with no crying if I shatter one.  The blanks have been really handy in the shop as nothing but fancy dowel pins and I was just curious if I could take them further without having to treat them like something more exotic.  To me, they're just something shiny in the "usable" scrap buckets.

When you have an asset, find a way to leverage it to YOUR best use, even if it doesn't follow the rule book.

 

[ThomasPowers]

Yup I pick up the solid carbide bits when I find them cheap at a fleamarket; I've had to drill a hardened blade before and a disposable bit lowers the stress level a lot...

[jlpservicesinc]

I bought a full section of HSS for using as guides for my 3613 bandsaw.. I ended up going with a ball bearing setup for the guides vs the blocks.  5/8"X3/4"

I ended up using the HSS for hot punches and hot work chisels..  It works very well..    Ideally the items with thinner shanks don't like to be used as prybars.. but as long as the the shock in in line with the shank they work very well though abusive to hammer faces as even in their soft state are still very hard so the striking ends need to be well rounded..  

Hardening media is air, oil or salts..  I find even left thing is the While being forged it likes to only be worked within a given range yellow to orange. Higher and it falls apart, colder well,  When it says hot hardness it means red hardness.. I damaged one of my hammers trying to forge in a blip on a tire iron I was making this was before I realized I had grabbed the wrong bar.. 

While the specs say depending on the kind/type the hardening can be complicated but  as forged the stuff is pretty hard.. 

 

A hardie made from this stuff would be pretty amazing I'd just hate to hit it with one of my good hammers.. Even left as forged and left to cool pretty slowly by the side of the fire it's probably 60HRc.. 

[patrick]

For M2 you really do have to get it extra hot to heat treat it becuase you have to dissovle the complex alloy carbides prior to quenching. With simple steels those are just iron carbide and will dissolve around 1450 F but once you start putting in vanadium, molydinum etc you really have to raise the temperaure.

[JNewman]

Be careful with HSS for struck tools especially with imperfect Ht.  I recall Grant Sarver mentioned a competitors shop having a fatal accident with a HSS tool shattering under the power hammer. This was under a large hammer but I remember him saying that this incident made him wary of using HSS tools under a power hammer.

That said in the right application with proper Ht they can give incredible results.  I have a pair of 1" square lathe tool bits that are in holders that I have cut thousands of 4140 and 4340 chisel points with.  I have never had to sharpen them. They are heat treated as purchased and they are supported in and pressed by soft mild steel so safer from shattering.