Bending SS tubing

[Jon Rosenstiel]

I have a length of 1/4", 0.035" wall stainless steel tubing that I want to use to connect the vacuum chamber to the capacitance manometer. I need a 90 degree bend with a radius of 2 to 2.25"

Could someone give me a few hints on bending the tubing? (I'd rather not ruin it right off)! Should I heat it? Or should I use a mandrel, or will one of those "coil spring" like thingys used for bending Cu tubing work?

Thanks in advance,

Jon
Rosenstiel

[guest]

You can buy a tubing bender at the hardware store that works very nicely and precisely, and will work for several different tubing diameters. They also show up from time to time on Ebay, but the bidding is usually fairly intense, and I never was ever able to get one for a price less than I finally paid retail for mine. One thing is useful, though - at least the posted pictures will show you what one of the beasts looks like...

[Tom Dressel]

A trick that we used in the Physics Lab that I worked in as a student, is to fill the tube with water and freeze the water in the tube with one end open. Then bend the ice filled tube, this prevents the tube from being crushed during the bend.

Tom Dressel

[DaveC]

You can also fill it with fine sand. Works the way the ice method does.The coil springs are pretty useful. You just need an assortment if you are bending different sizes. Personally, I like the regular tubing bender, that Richard Hester mentioned. Most of them also have some marks to indicate the number of degrees you have bent, which makes is nice for repeat bends of the same angles.

Dave Cooper

[DaveC]

You can also fill it with fine sand. Works the way the ice method does.The coil springs are pretty useful. You just need an assortment if you are bending different sizes. Personally, I like the regular tubing bender, that Richard Hester mentioned. Most of them also have some marks to indicate the number of degrees you have bent, which makes is nice for repeat bends of the same angles.

Dave Cooper

[Jon Rosenstiel]

Hey guys, thanks for the good info. I was not aware of the small bender Richard describes. That puppy will do some pretty tight radius bends!

I ended up using the "spring-like thingy" as I didn't need a very tight radius on my bend. Worked well.

Regards,
Jon Rosenstiel