[Todd C]

I assume you are refering to a firearm. The SS used in a frame isn't very hard and can be machined the same as a carbon frame. SS is a little tougher, so I use carbide (I use carbide almost exclusively, anyway) and some cutting oil.
Slides can be harder, so be sure to use carbide for any tool life. Keep your cutters sharp. As far as cut depth, your setup will probably dictate a fairly light cut. When I sierrate a slide, I take the full depth at once...It's only about .013", anyway, and have no problems. Sight cuts are deeper, and I only go about .020" at a time (except for dovetails which have to go full depth in one pass, of course.)
I hope this helps.

 

[George Smith]

Todd is correct, most guns slide and barrels use 416 ss
they add sulfer to 416 to make it free machining, drilling a hole 30" long is no easy task, free machining steel helps a bunch. 416 is what I call Just stainless, it is magnetic and it will rust. Sweat under grips being one of the most common problems.

if your using Hss try 50 surface feet per minute
with carbide depending on your set up you can go to 225 sf. 4140 is tougher than 416 in every way.

geo

 

[cowboy1]

Thanks

Yes it is a gun. It is a Caspian frame and slide. I need to cut everything except the rails. Need to flatten the top cut sights, do the grip and cocking serations or what ever I put there. Project to start in several weeks.

 

[steveno]

if you do a lot of this kind of stuff I suggest you invest in a copy of Machinery's Handbook from Industrial Press. It will cost you somewhere around $100 but every machinist either already has one or should have one