Spacers, tubing with very thick walls?

bushing?

try balsa wood

McMaster has Garolite rods and tubes, but not 0.866 OD - the closest they seem to have is 1/4 ID x 3/4 OD tube, or 7/8 rod.

How many do you need? If it's in the hundreds or thousands, the shop where I sit could quote it:

Don't know but I suspect you'll have to get something made or make it yourself. Tubing is never exact size, or even perfectly round, and there is often a seam up the inside.

McMaster Carr, among others, sells standoffs in various diameters and lengths.

I am not exactly sure what size a 608 bearing is but would a

To get tubing without a seam, search for "DOM" or "Drawn Over Mandrel" tubing as it is not welded or cast. It is essentially... well... Drawn over a mandrel or precision extruded.

It's what they use when they need the strongest option as well as there are no hard spots created while welding the seam.

Regards, Joe Agro, Jr. (800) 871-5022

Tubing, even DOM, is also rarely concentric.

Bar stock with a hole bored in it. What lathes were made to do.

Stan

Oh contraire! DOM IS welded! I toured Trent Tube in WI and was amazed at the process. It all starts out as coil stock then it goes through a series of rolls that form it into a tube then it's TiG or laser welded, cut to length then drawn over a mandrel in lengths equal to the length of the mandrel.

Wow... Very interesting. Never would have thought that is the way it is done.

Thrust washer or bushing

If you want seamless, you specify "seamless", which is made by a rolling process.

Yeah, seamless tube is "drawn over mandrel" of necessity but, drawn over mandrel is not necessarily seamless tube or pipe.

If you are in this racket it helps to know the ASTM specs!

Wolfgang

laser welde

FWIW. I had ordered some from McMaster Carr for another purpose, they call aluminum seamless tubing "single-line". Their description is "Formed from a pierced cylinder of material, creating a uniform tube without a weld or seam."

DOM usually is first resistance-welded -- often submerged-arc welded -- and then drawn over a mandrel to flatten the weld and to produce a fairly uniform strength, hardness, and diameter. DOM may be shrunk from its original diameter by extruding it through a die while it's being drawn over the mandrel.

Plain ERW, like EMT and common tubing of various types, may be sort of drawn or rolled over a mandrel to flatten the weld, but it's not fully reformed over a mandrel.

Seamless is pierced from solid bar and drawn over a mandrel. Once upon a time it was the best tubing, but DOM made from flat sheet is so good today that the performance is nearly identical. And DOM made from flat sheet generally has more uniform thickness.

Some German tubing company had a miniature DOM machine at IMTS one year -- either '78 or '80 -- that was about six feet long and produced soda-straw-sized tube from a flat strip of steel. I would love to have one of those toys. It was really fun to watch.

In terms of pricing, ERW is the cheapest and seamless is the most expensive. There also are some other methods used to make tubing today, including a spinning method that produces a friction lap-weld. These came after my time covering materials so I don't know anything about them.

Maybe I should have been more specific, but a 608 bearing is a common piece of hardware.

I should have added that it's generally rolled after piercing, too.