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From: "Lloyd E. Sponenburgh" lloydspinsidemindspring.com
Sent: Friday, February 21, 2014 4:52 AM
Newsgroups: rec.crafts.metalworking
Subject: Best Bet for Mystery Steel
"Bob La Londe" fired this volley in
:
I've got a piece of mystery steel about 2' x 6' x .78". It was given
to me by a friend when he was moving. I have a couple projects for it
that are going to require machining. What would be the best guess for
the alloy to machine conservatively but without killing cutters? A36?
1018?
Man! Bob, that's a honkin' beeg chunka metal for a small shop guy!
Bob, inspect it fully before guessin'. Can you scratch it easily with
hand
tools?
Grabbing a scratch awl right now.... BRB ~~ I can scratch it some, but its
hard to tell if I am scratching the base metal or just the rust and paint.
Is the surface perfectly smooth (ground) or does it look rolled.
Its hard to tell. It was paited at one time, and now its about 50% rust and
50% painted surface. The rrust is not heavy scale rust, but in SQ Arizona
tat doesn't mean much. I know of unpainted homemade trailers with just a
surface layer of rust.
Was it sawn off the mother stock, or does it show a shearing snipe on one
end.
Both long sides were cut with a torch. The up end has a slightly concave
surface that looks neither sawed nor sheared to me. I can't look at the
other end easily. If I lay it down I'll need help to stand it back up. I
figured when I was ready to work on it I would rearrange some equipment and
move it with the tractor.
Does it possess any gray mill scale on the surface, or is the surface
completely clean and rusting?
Can't tell, but it has a light layer of rust and paint.
Does it rust?
Yes, but the exposed surfaces are not completely rusted.
Pick and edge, and just start to drill a hole with a 3/16" bit. If it
cuts
nicely with a little oil, you can consider it plain A36 hot-rolled, even
if
it is 1018 really.
I used a TiN coated 3/16 bit and some Tap Magic. It drills it ok, but I had
to lean on it pretty hard. I thought it wasn't going to start at first, but
the tip of the bit could be a little dull.
1018 machines a bit more easily than A36, so if you go
with the recommended feeds-n-speeds for A36, you'll be safe.
Both alloys can be had in ground flats, but that's expensive and unusual
to
find in pieces that wide. Now... if it's ground, doesn't rust much, and
is
hard to mark/drill... you're on your own! G
Its got a *very* slight bow to it in the long direction, but there is no
telling what it has been used for over the years. I was thinking about
torching out a section to make a lathe chuck adaptor plate for my new
independent jaw chuck. (and some other projects). I don't have anything
else laying around big enough to make the adaptor plate. Figured I would do
everything on the mill, and then turn the final boss for the new chuck on
the lathe its going on.
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