How to harden this cone ram?

[mccutter]

I use this cone ram to expand the ends of 3/4" painted steel pipe cut to about 3". Each end is forced open with the press, then the tube is cut diagonally in half, sharp edges cleaned/smoothed, then a quick coat of silver paint. They are used to prevent wear from MC cable being continuously rubbed against aluminum. I call it a "wear cone".

One of the pics shows the ram in the little HF lathe. This is the 2nd or 3rd time I've cleaned the ram up. It will last about 30-40 cones before it starts getting scratched and transferring the scratches to the cone. I think it is made of tool steel, whichever flavor, I don't know.

I have O/A torches and/or self clean oven available. Is there a way to harden the cone so it is less likely to scratch?

[digr]

Would a dead center for a lathe work, hard and cheap

[Scotts]

If it is made out of tool steel is is hardened after you make the cone?

What are you using to machine the cone with?

You can get oil and water hardening steels you can make stuff out of then heat it up and harden it.

Scott

[greywynd]

Without knowing what steel it is for sure, it’s a crapshoot as to how to harden it.

Best bet would be to buy a piece of O1 oil hardening steel. Turn your angle, heat to red hot, and quench in a bucket of oil. Tempering can be done in a house oven if I recall the temps right.


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[toprecycler]

It may or not be able to harden. But what have you got to lose? Worse case you have to make a new one.

Heat it up red hot with oxy act torch, then cool it in a bucket of water. Take care to keep moving it in the water.

Check hardness with a file after. If it still files, get another piece of known flavor of steel that will take a hardening treatment.


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[arizonian]

Make one out of O1 tool steel, heat it until a magnet won't stick and then quench it in vegetable oil heated to 300F. Leave it as is. The extra hardness will go a long way towards minimizing wear down the road.

I wonder if a little paint beforehand will act like a lubricant.

[milomilo]

Do you lube it when pressing?

[mccutter]

Originally Posted by digr

Would a dead center for a lathe work, hard and cheap

That's a good idea! Probably going to need at least a MT3 or preferably MT4 taper. The little HF is MT2 taper and did not come with a dead center. The OD at the largest point would need to be at least 1" dia. My cone is 1-1/4" I think.

Looking on debay there are plenty of import MT3 in the $15 range. The 60^ angle is a little more obtuse than I'd like. I think mine is about 45^. Another issue is with only a carbide point, how hard is the rest of the center?

There is a well-used MT4 for $16 that looks to have a-cuter angle although construction is unknown.

[mccutter]

Originally Posted by milomilo

Do you lube it when pressing?

I always go in dry...

I'm sure a little oil will help but make the operation messier... I do clean up/deburr the insides of the tube so they are less sharp. I'll have to pay more attention to knocking the weld down inside.

[digger doug]

Originally Posted by mccutter

That's a good idea! Probably going to need at least a MT3 or preferably MT4 taper. The little HF is MT2 taper and did not come with a dead center. The OD at the largest point would need to be at least 1" dia. My cone is 1-1/4" I think.

Looking on debay there are plenty of import MT3 in the $15 range. The 60^ angle is a little more obtuse than I'd like. I think mine is about 45^. Another issue is with only a carbide point, how hard is the rest of the center?

There is a well-used MT4 for $16 that looks to have a-cuter angle although construction is unknown.

Buy one without a carbide point (or if it snaps off, I think it is small enough dia, it won't bother you)
If you want a lower angle, consider mounting a grinder in the toolpost,
and grind the angle in the hardened center.