slot cutting in stainless steel tube

[brbeardm]

I have some 3.5" diameter stainless steel tube (16 gauge) that I want to cut a 1.80" x .125" slot with a slotting cutter along the outside diameter of the tube (perpendicular). I'm looking at a .125" carbide slot cutter from iscar... i think with 56 teeth that is designed for stainless steel...

My question is... what diameter slot cutter should I get... should I set it up at the center of my cut and have the front of the cutter do .90" and the backside of the cutter do .90" ... i'm worried about the backside cut lifting up the tube causing distortion.... or do i buy a small diameter slot cutter like 1" and cut from one end of my 1.80" length to the other end moving through the material...

Can anyone give me some guidance here... best way to get a clean cut in the tube with no distortion

my other option is to take to a shop to have them laser cut the 1.80x.125 slots... but this is costly for the setup, etc... and I'd like to do it myself if it can be done on my mill/lathe

[Shane123]

a thin wall tubing is going to be a pain in the butt slotting. it will wanna move, cant clamp down with your vise harder or you will bend the tube....... if you can, use a couple v blocks and strap it to them with your tnut hold downs, and keep it as close to the groove as possible. then take light depth cuts till you break thru, .010 is about right. the longer the groove, the worse off you are. you might wanna rethink the laser cut option, really.

[Geof]

Originally Posted by Shane123 ..... you might wanna rethink the laser cut option, really.

This is good advice. Doing it yourself is likely to lead to a lot of cost in broken slitting saws. On tubing that thin really the only way to grip it is to have a piece of round material inside to support it. This is means the slitting saw will be cutting the material inside which will make it more or less impossible.

[Shane123]

the only other option i can think of is if you can squeeze the saw cut ends instead of the diameter. would be the most stable at that point.