Speaking Of Cutting Stainless...

[Rick D]

(Rather than taking another thread in a different direction)
So I was modifying a bimini frame. I screwed up bending it, so I had new legs made up with the intention of splicing. So, I had to remove the old ones. I had a tube cutter that worked well on regular tubing, but it was a mess with the stainless. Finally decided a cutting wheel was worth no more than two cuts, so I bought a bunch. Still took a lot of swings to cut a tube.

Then I had 1" ID external sleeves made up to connect the tubing. I had them drilled for 1/8 s/s rivets to keep them in position. Well, drilling four holes in the female stainless was a nightmare. I used three 1/8 bits which were five bucks a piece at ACE and supposedly for hard metal drilling, and tried drilling with two smaller bits first with limited success. And, it took forever.

So, what am doing wrong? Stainless guys don't make money taking that much time. I used a low to medium RPM and tried a variety of pressure. Slow RPM and heavy pressure seemed to work the best. I have also found that hack saw blades dull super fast even with top quality.

So, what are better methods and/or cutting materials?

 

[Tejas]

This what I've used good success on thin-wall stainless tubing.

http://www.amazon.com/gp/product/B001P81OK6/ref=oh_o00_s00_i00_details

 

[caguy]

A radiac blade with your chop saw works well.

 

[Don12364]

Work Hardening

It is all about 'work hardening'.
Even on the first rotation of the drill you need a heavy pressure, slow speed and lubricant for cooling - and a sharp drill.

The instant the drill rubs rather than cuts, the surface of the stainless work hardens and is then harder than the drill.
It can be an intimidating proposition but you need to use as much pressure as just doesn't quite break the drill.
If you are really brave the job is then often quite easy.
Once you have spoiled the surface no other drill will touch it and goes blunt immediately - though you could try a carbide drill or a carbide tipped one.
The same applies when sawing but at least an angle grinder can get one out of difficulty.

 

[Cool Beans]

When I did my upper chain plates I drilled 18 holes through 1/4" S.S. bar stock and it was as easy as drilling thru plastic. I used a 3/8" cobalt drill bit with the pilot tip, and the slowest setting on my drill press, and a LOT of pressure. I didn't use any cooling fluid. Every hole put out a continuous ribbon of S.S. while I drilled :dance:

Don is right, go slow with a lot of pressure and don't stop till the hole is done. I really recommend a cobalt drill bit, and I really like the pilot tip ones for metal work. The bit is still sharp and still in use.

Also a tip. . .if you do slip or dull out the bit and work harden the piece. . .you can always drill from the back side with a sharp bit and finish the hole. It's only the surface that the face of the drill bit was cutting that turns rock hard

 

[alexco38]

Cool Bean is right Cobalt bit is the best just go slow. Always drill small pilot hole. I can cut with home depot pipe cutter again go slow. You can sleeve 1 inch pipe with 7/8 as the wall is 1/16. You have to Drumel the inside to fit over the 7/8. I also found that marine epoxy can join the pipes very well. No holes or screw heads.

I raised my dodger to just below the lowest point of the boom. When sailing I almost always look out from the side. Higher dodger wont hit my head when going into the cabin. Something to consider.

 

[Rick D]

I was going to sleeve it inside, but the new legs I had made up were a heavier gauge, so the ID wasn't right. Ergo, the outside. hadn't thought about adhesive. Oh well, done now.

 

[Rob2435]

When working with SS, slow is always better, keeping it cool and plenty of lube.

 

[tommays]

Speed kills but i do have the advantage of working with the stuff everyday at work

A plain old black oxide 135 degree split point #21 bit for less than a buck will make dozens of pilot holes with a hand drill and some fancy liquid wrench white lithium

 

[Rick D]

Thanks Guys...

It's clear to me from your comments that I screwed up when I took a break when drilling. I probably work hardened the surface. I hope this will help the next one in their drilling of s/s!

 

[Manureva]

my plasma cutter usually makes a quick work of any cutting job with stainless!