High Speed Steel?

[VicParticipant @vic]

If you have a moment, have a look at this video and let me know your thoughts on using HSS for this tool.

I’ve always been lead to believe that heat treating HSS in the home workshop isn’t possible?
Do you think using HSS like this is better than say O1?

https://youtu.be/istT2TVr_QU

[BazyleParticipant @bazyle]

Although he might have ordered HSS off ebay it is quite likely not what we call HSS, ie a complex alloy but just a high carbon steel with maybe a bit of modifier. I don’t think a good HSS bends at a mild red heat.

The reason amateurs can’t heat treat the proper stuff is that they don’t know what it is and hence what the phase diagram is in order to plan the process. There must be a thousand different formulations in current manufacture and no end of old stock out on ebay and the far eastern markets. then you do need a proper furnace controlled to the specific temperature not just er ‘reddish’.

[FulmenParticipant @fulmen]

Could be “drill rod”, aka yankee silver steel.

[David George 1Participant @davidgeorge1]

The steel welded on to the stem is not HSS The colour of sparks were not correct and should have been more of a red colour. The way it was bent to me says it is 01 ( Silver Steel ) if it was hardened in that manner it could cut wood fairly effectively as I occasionally make  cutters and taps from Silver Steel.

David

[Fulmen]

On Fulmen Said:

Could be “drill rod”, aka yankee silver steel.

I agree!  99% certain he’s using Drill Rod, what we in the UK call Silver Steel.   At one point he files it, then finishes by simply plunging the red-hot item into oil.  That’s not HSS.

HSS is carefully formulated for toughness and to stay hard up to red-heat.   Depends on the alloy mix plus a very elaborate series of heat-treatments lasting several hours.   Temperatures and soak times are critical and three or four precision ovens are needed because  the steel can’t be allowed to cool between stages.  Unlikely that the specialised kit needed to heat treat HSS will be found outside a factory.  And having the ovens isn’t enough!  As Bazyle says, also necessary to know exactly what the alloy is because the process is matched to it, and there are many different High Speed Steels about.  Bottom line, we buy HSS in the hardened state and grind it to shape. It can’t be annealed, tempered, or rehardened.    Even normalising is difficult.

In contrast, Silver Steel and Gauge Plate are carefully formulated to simplify hardening and tempering using ordinary methods.  Supplied soft so it can be filed and machined.   Hardened simply by heating with a torch to about red-hot, and then plunging in oil or water.  Tempering can be done by chasing colours with the same torch, or soaking in a domestic oven.   Silver steel is ideal for making wood-working and metal cutting form tools.   Not as hard-wearing as HSS, but it’s good stuff.

I liked the video, but beware the internet! There is no quality control. What you get varies between excellent and awful.  Quite fun spotting mistakes.  In this one, it’s the phrase “HSS Drill Rod”.  Probably a typo or brain-fart: it’s just “Drill Rod”.

Dave

 

 

[Michael GilliganParticipant @michaelgilligan61133]

Nice tool, and well-made

But the electric welding of ill-specified materials is risky.

MichaelG.

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[Michael GilliganParticipant @michaelgilligan61133]

To fuel the discussion of ambiguity …

https://www.cromwell.co.uk/shop/cutting-tools/drill-blanks/c/391501

MichaelG.

[FulmenParticipant @fulmen]

I’m with you Dave. Some of you might remember my attempt to anneal a large HSS drill, and that stuff is a royal pain in the * to work with. I actually cracked it the first time, and I was only trying to anneal it. I’ll go so far as to say that HSS is the wrong choice even if you could do it somehow.

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