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fr334g3nt
02-08-2011, 01:03 PM
Hey Everyone,

New guy with a question.

I have a shop press that I want to make some pushing adapters for, but have no expertise in metals. I'm currently using 316 stainless for my pushing adapters but the press is 30T and some of the adapters are bending/contorting.

I'm thinking of using 4140 instead because in my limited research it seems stronger than stainless.

But is it safe?

I know that I don't want to use any tool steel in there, but what else?

I want to live a grenade free life.

My current safety precautions include lexan and an old cast iron oven door.

TIA

Dr Stan
02-08-2011, 01:17 PM
4140 would be good, but so would 1018. Over time any material will suffer some deformation when used in this manner, so you should consider them to be consumables. I've used brass and aluminum adapters on occasion just to reduce the possibility of damaging the work piece.

Your aversion to tool steel is leaving me a bit perplexed as this is the material used in die sets that are subjected to pressures much higher than 30T. It also depends on if the material is in its normal state or hardened and just how you are using the adapter(s).

Toolguy
02-08-2011, 01:21 PM
Half hard, pre hardened, 4142, brake die steel - are all names used for 4140 that has been heat treated to around 30 Rc. It's easy to machine with HSS. It is usually what is used to make bending dies for press brakes. Any 300 series stainless is fairly soft and deforms easily.

fr334g3nt
02-08-2011, 01:28 PM
Thanks for the replys.

My aversion to tool steel just results what I've been told by two different machine shops. They told me that it has a tendency to shatter when it breaks as opposed to mushrooming/bending/buckling.

So, as someone who knows very little, I want to do whatever I can to minimize the danger part of the old saw "knows just enough to be dangerous"!:D

fr334g3nt
02-08-2011, 01:31 PM
So if I was to buy this:
http://cgi.ebay.com/1-1-00-4140-4142-CFA-Alloy-Round-Bar-Rod-Shaft-12-/180431945829?pt=LH_DefaultDomain_0&hash=item2a02950065

This is pre-hardened material?

Jaakko Fagerlund
02-08-2011, 01:55 PM
Thanks for the replys.

My aversion to tool steel just results what I've been told by two different machine shops. They told me that it has a tendency to shatter when it breaks as opposed to mushrooming/bending/buckling.

So, as someone who knows very little, I want to do whatever I can to minimize the danger part of the old saw "knows just enough to be dangerous"!:D
That dependsw totally on what the steel is and what is its hardness. Sure, if you use 1.2510 hardened to 63 HRC, it will break like glass, but if properly annealed to around 48-52 HRC, I'm sure your press will bend before that gives.

Toolguy
02-08-2011, 02:01 PM
fr334 - That material is annealed which means soft.

wierdscience
02-08-2011, 03:11 PM
No cast iron,ductile iron or cast aluminum.

Be wary of things like V-blocks,make sure they are steel.Some of the import presses out there have cast press plates,not good.

I have two sets of HF deep impact sockets I use for pressing shafts out of bearings,they are cheap,hardened and come in a variety of diameters.

Basically so long as it's steel and the ends are machined square you should be in good shape.

winchman
02-08-2011, 03:35 PM
Keep in mind that it's not the tonnage of the press that's important; it's the tons per square inch on the piece you're loading.

gda
02-08-2011, 04:02 PM
No cast iron,ductile iron or cast aluminum.

Be wary of things like V-blocks,make sure they are steel.Some of the import presses out there have cast press plates,not good.



+1 One day I had some cast V-blocks in the press - not really thinking. I got a bruise on my shoulder when one exploded in half with not that much tonnage on it.

Dr Stan
02-08-2011, 07:06 PM
No cast iron,ductile iron or cast aluminum.

Be wary of things like V-blocks,make sure they are steel.Some of the import presses out there have cast press plates,not good.

I have two sets of HF deep impact sockets I use for pressing shafts out of bearings,they are cheap,hardened and come in a variety of diameters.

Basically so long as it's steel and the ends are machined square you should be in good shape.

Everyone should heed Weirdscience's advice as it is quite good.

Big T
02-08-2011, 08:20 PM
Do not use wrist pins from connecting rods/pistons.

They will also chatter.