Stainless steel mandrel trials
 

I have recently launched an experimental trial to identify the best grade(s) of stainless steel for beadmaking mandrels and am hoping as many people as possible will join.

This is not a profit-making exercise - though I am "marketing" it through my Etsy shop and I hope to recover my costs eventually if enough people take part. I will make the results of the exercise available to anyone to who wants to see them or make use of them.

I am in the UK, so international shipping costs may be a problem but perhaps some of you may be interested in any case. Check it out here - www.etsy.com/uk/listing/231654533 - and contact me if you want more info.

I've been using 316L steel for many years with excellent results.

Robert

I think that's what most people use, partly because of availability and price. Its main disadvantage is becoming soft and bendy after quite a short time - not such a problem with thicker mandrels as with thin ones, but there are other grades that stay harder and straighter for longer.

You can re-harden these mandrels by getting them hot and cooling rapidly by dipping in cold water. I very rarely have to do this but it does work if you need it. The only sizes I've had problems with are 1/32 and 1/29 inch. The 3/32 have lasted a couple of year without issue.

Robert

Thanks for the info, Robert.
1/32" is seriously thin! How big do you manage to go with beads on that size of mandrel? As you say 3/32" (and upwards) should be good for a long time, though I've destroyed a few working boro in a hot flame...

It's all about heat control and keeping the flame off the mandrel as much as possible. I oncemade a set of 2.5 inch long hair pipe beads for a necklace that my wife made on 1/32 mandrels (12 black, 12 dark red). It wasn't easy.

Robert

One of the larger issues is chromium migration with repeated heating and cooling cycles.
Things tend to rust, paticularly in humid environments.

410 is usually a stronger alloy and works a bit better with boro
More prone to rust over time

302 and 304 work and is available in much smaller sizes.
but it anneal at a lower temp and can be bendy or springy.

308 and 316 is fairly common

You might want to check azom.com or matweb for metalurgy details.

I've not found a source for 1/32, but routinely use 5/64 and love them, especially for earring pairs and spacers. Mine have lasted many years, but on smaller beads I'm not so particular about the mandrel being straight as long as the last inch and a half is ok. Spacers are boring, so using a bent mandrel adds a layer of interest since the brain and left hand have to work harder to keep the straight part level. :lol:

I have used both 308 and 316 and see little difference between them.

I use 308L that I get at the local welding shop in 36" lengths. Cut with husbands metal cut-off saw. Grind sharp edges.

Thanks for all the input here - much appreciated.