The Armour Archive

I want to roll some edges on a piece in Stainless Steel (greaves). I've been told hot rolling is 'easier' for stainless.

What do I use to heat the edge to roll?

Any Tips, tricks, etc.?

What tools do you have and what alloy are you useing?
A rose bud tip on an Oxyfuel rig will work.

You CAN do it with just a MAPP torch but it will take a long time to heat and you will be working at the low edge of red at best. Hot steel is still hot and still softer then cold even as it falls into the black. I have an Oxy-Mapp torch also from Home Depot that can almost weld but is mostly good for brazing. It will heat much quicker, but the O2 is expensive and the tip takes longer to adjust then the steel takes to cool down so I have to clamp the handle in a vice and leave it running. That's expensive but works for an important project. One of these days I'll get myself a professional oxy-acetylene torch but I have other priorities first.

Sean

Coal forge, charcoal forge, propane forge, torch, induction forge,....you use what you have or can construct or buy.

I find it quicker to do it cold since heating takes time. Working hot I use a charcoal forge

Stainless also anneals/normalizes differently depending on the alloy.
If your using a propane plumber style torch spend a few extra bucks for an adapter hose.
The larger 20 lb tanks wont freeze up like the smaller ones do and its a butt load cheaper for a refill.
I have a mounting built to hold the torch on my bench for glass work built from a piece of angle bracket, pipe clamp, and C clamp.
An L shaped backer made from fire brick will also help speed up the process.

I only have one of the Benz-o-matic blue can torches.

That's for brazing copper pipe. You'll want a way to deliver more heat, and sufficient heat over an area. You'll go through a lot of Bernz-O-Matic cans right quick if that's all you use.

Propane & forced air or propane & oxygen, and a roof-burner type of flame nozzle such as the people who tar roofs use, seems more the ticket.



Here's a homebuilt. Well, caveat ignitor.

Is it 'better' to hot roll stainless?

YES! NO! MAYBE! depending.

bigfredb wrote:Is it 'better' to hot roll stainless?

The benefit is in moving the hot section where you want it to be with less force and not unintentionally moving the cold section. If the piece shape is approximate and the occasional flatening or cupping won't harm it then cold is usually fine.

You do have to remove scale after working hot and that also adds time and cost. People talk about putting carbon into the stainless which promotes rusting... which is technically accrate if you are in a salt-water, food-grade or medical application and only wipe the soot off but if you do any chemical or physical cleaning then the carbon affected layer is largely removed and it's not an issue.

Sean

bigfredb wrote:Is it 'better' to hot roll stainless?

Rolling is what the mills do, we work. Hot/cold working.