Picked up some stuff from a closing down factory. Taps and some
stamping sets.
The owner also gave me a few dozen pounds of tool steel. They were
little bricks of steel, the owner said that they were tool steel.
Since they were free, I assume he was telling me the truth. My
question is, is there some easy home method of identifying what that
tool steel is. It looks shiny, like HSS in drill bits. Thanks.
i
$75-$100 each lab test. Been there, done that, although I had a ton and it
was worth it. After I made some parts on an assumption that bit my ass, I
resigned myself to do the right thing.
First you can compare the sparks it gives from a grinding wheel to a
known piece of steel and see if you can match it up. This will put you
in the ballpark. You can also heat up a piece untill it loses its
magnetic attraction and then air cool it. If it gets hard it is an air
quench steel possibly A2. Do the same thing again with an oil quench
and see how hard the surface gets. O1 steel is a lot cheaper than air
quench steel but the air quench doesnt move as much when its quenched
and will give you better thru hardness.
There are so many types of tool steel you reall have to have it tested
if you want to know the exact type it is.
John
Thanks John. I will see what I can do. What steel are drill bits and
taps made of?
Anyway, I was kind of hoping that there is a kit with some chemicals
that I could brush on, if it turns pink it is A2, if it is purple it
is 4140, etc. Seems like there is no such animal.
i
Well, you can do a spark test on the grinding wheel and compare it to a
known alloy. Reading sparks is an artform in itself. Got any
old-timers around?
Ig:
SAE 4140 is not classified as a cutting tool steel. It is a high
quality machinery steel that can be heat treated to through-strengths
of over 200,000 psi in sections 2" dia. or less.
However, some people I worked with made paper cutting label and
envelope dies from this stuff, hardened right-out to Rc 52. The
customers seemed to like it.
It is really more suitable for hard-working components such as shafts,
work and tool holders, pinion gears, arbours and mandrels, draw bars,
in short anything that needs to be strong and tough.
Cutting tools such as drills, raps, reamers, etc. are nowadays made of
high speed steels of varying types and qualities.
Try to lay your hands on a little booklet from Crucible Steel Service
Centres: Tool Steel and Specialty Alloy Selector. Most informative.
Wolfgang
For stainless identification acids are used, but I don't remember the
exact procedure. You brush it on and watch for any discoloration.
Its not that hard to distinguish carbon steel from alloy steel. The
spark test will put you in the ballpark with carbon steel, and a quench
and hardness test will give you an idea of the carbon content by the
hardness. 1018 will not get at all hard. 1045 will get to about 54
rc. ( a file will scratch it but not too deep). 1095 will get file hard.
John
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