tempering a miners pick??

Gday all,
The job at hand, sharpen a miners pick.
The work sofar:- made a set of hammer-eye tongs with a ring to hold
the pick head while working on it(I can supply a pic if you want
one). Drawn out the points on the pick so both are longer and
sharpish - its not a surgical instrument, so it don't have to have a
fine edge. Hardened both points with an oil quench - I didn't want
it to be too hard and brittle.
Ok, so now the question. What colour should I temper the points
too??
I've looked in my selection of smithing books and can't find an
answer.
Has anyone here done this job before? What colour did you use and how
did the tool hold up after tempering?
Kind regards
Rusty_iron
Reply to
Rusty_iron
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Temper to straw colour if you want to cut stone ;-) Charles
Rusty_ir> Gday all,
Reply to
Chilla
I'd be interested to hear how this works out.
Pete Stanaitis ---------------------------
Chilla wrote:
Reply to
spaco
The information came from a guy that makes stone cutting tools :-) Charles
spaco wrote:
Reply to
Chilla
Thanks Charles. The job is for a guy who prospects, so I imagine he is digging and striking stone all the time.
Pete, I'll let you know after the job is finished - may be a few weeks I cricked my neck yesterday, so no heavy work.
Do we have any other ideas on what colour to temper too? Anyone? I'm still interested in other ideas, for comparison.
Regards Rusty_iron
Reply to
Rusty_iron
Sounds like what I read a in a blacksmithing book once. :) (no kidding)
And it sounds good to me anyway... color-up everything except the tip and as the tip turns straw... cool it quick.
Sand it and do it twice?
Be interesting to hear-back how "filable" the tip is when you get done whatever you decide.
My cowboy buddys don't re-heat treat them just leave them soft and they wear -fast-. I've had better luck just grinding them to a new point. But mine were for ditch digging at work. I liked to take the extra-heavy ones we were supplied in the signal department (9 pounds) and grind down the wedge shaped end into a long thin square coming to a point.
Lighten that sucker up some on the other end too for my skrawny little ass. :) I've had two different RoadMasters special order 7-pound picks with points on both ends just for -me-. :)
I did a lot of volunteer track work and they knew it.
Alvin in AZ (retired RR signalape)
Reply to
alvinj
If it's going to be used for breaking stone, I'd basically treat it as a big (double ended) cold chisel:
Blue at the tips, tapering to pale straw at the eye.
Heat to non-magnetic all over, quench the ends, temper using the heat stored in the centre, then quench completely.
Not easy to do if it's a full size (24lb?)/30inch wide road pick, but it can be done.
Reply to
bigegg
Hi Bigegg,
That would make the steel softer at the tips and harder at the eye.
From a very good book :-
Straw cuts stone Bronze cuts steel Peacock cuts wood Purple springy Blue soft
Heat from the eye out, this way the eye is soft and the cutting points are hard.
Regards Charles
Reply to
Chilla
I think you have it backwards. It you let the color run out from the eye (assuming that you only quenched the whole thing down to about 600 degrees or so), the eye will be at the higher temp (blue) and the ends will be straw (if you stop in time). For this to work (and it does) you have to ready to polish those bits pretty quickly so you can see the colors running. Since you won't have time to polish the whole tool, you probably won't see any temper colors at all in the area of the eye, since the whole thing will be covered in scale as you pull it out of the quench.
Pete Stanaitis ------------------------
bigegg wrote:
Reply to
spaco
You're right Pete.
You wouldn't need to remove all the oil crud from the tool, only one of the faces needs to be exposed. You can safely assume (in this case) that what happens to one side will happen to the other. You would only need to expose an inch or two on both ends of the tool and only on once face.
Pete, it sounds like you do the H&T in one operation. I prefer to do the temper in a separate step, especially with a large piece of steel, but that's my preference. I'm a wuz when it comes to holding a really hot piece of metal :-(
Regards Charles
Reply to
Chilla
I do it both ways. I use separate operations for things that are (to me) critical. I am not too keen on "tempering on the run" anyway; I see it as quick and dirty practice, and only to be used on plain carbon steels anyway. I just did a couple curved leather punches out of 1095. For them, I did a separate temper.
Pete Stanaitis -----------------------------
Chilla wrote:
Reply to
spaco
Oh bum. I did, of course, get the colours the wrong way round - sorry
last two or three inches on the blade is usually enough, but you have to do both ends - I use a 9in angle grinder and give it a skim along the back. Takes 2-3 seconds to run a bright line 3/4" wide the full length
Reply to
bigegg
That's a good idea.
Pete Stanaitis -------------------------
?
- I use a 9in angle grinder and give it a skim along the
Reply to
spaco
I see it used in a repetitive-task situation first, then later it's just another learned skill to show off or use quietly. ;)
The same with straightening a freshly quenched steel part before it's formed too much martensite and is still plastic.
For sure, I haven't developed that skill, but can see where a guy could, in the right repetitive situation. :)
Alvin in AZ
Reply to
alvinj
I just wanted to say a guy at work, back in the mid 60's, was using a factory made pick and the pick broke in the eye and one half ended up hitting him in the head.
Nothing serious because there were fellow ditch diggers to help him but it could have been.
Alvin in AZ ps- building the new Magma Jct to Coolidge line, an Indian Rez bypass, lease ran out and the injuns;) wanted soooo much money to renew the lease it was cheaper to build a new bypass line :)
Reply to
alvinj

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