I have been working quite a bit with stainless steel fasteners in the past six months or so.

We are using various sizes, ranging from 4mm to over 20mm. You need to be aware that once SS fasteners are tightened or torqued to spec they very often seize together. Anti-seize will prevent this.

If you forget the anti-seize and you need to separate the nuts from the bolts you are going to have a problem. On the small fasteners you can sometimes simply use enough torque to shear the bolts and replace them. On the larger diameters you can use a cut off wheel if there is room enough to get the tool into position, otherwise it can make for a bad day.

Randy

I worked for a contractor installing traffic light signals. All hardware was stainless steel. We used wax on the threads to prevent seizing. The cheapest method is to buy toilet bowl sealing wax rings, and smear some wax on the threads.

As you wrote, stainless bolts screwed into stainless nuts often seize.

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john

Hi Mr. Starkie!

Sure Happy it's Thursday (all day longt)! Hope everybody and the Volvo autos are all aces and eights, in the pink, and right as rain!

Yep, galling using stainless to stainless fasteners. It got worse with the made in chinesium stainless fasteners in the factory. Look at the thread of US made stainless fasteners versus eastern Pacific nation made under magnification using a Jeweler's loupe or greater magnification. Also, some Europa made stainless fasteners are well made.

You already mention anti-size? What do you use?

We also used thread lubricant and adjust (reduce) the torque value in the event of field or return to the factory for disassembly and repair. There is some formulate the ME or manufacturing engineer would use to figure torque, yet we also used flat and lock washers or KEPS nuts (lock washer that spins, yet is secured to the nut). Did not always work on disassembly and would have to cut. Also, vibration means a need for additional blue or red thread locker.

(Heh-heh, try to get a torque value from an ME for a securing hardware material stack set! Ha-hA you imagine them as sometimes CYA while bolts or embedded fasteners break away from the housing. I'm just the tech writer / illustrator.)

The stainless chinesium hardware like from Fastenal always seemed very soft for like 300-series stainless.

Anyhoo, some articles for you that I hope help your causes and cure your stainless fasteners and all other woes and concerns (like why not year round eggnog)!

Fastenal - Galling (PDF file should open in Mozilla FireFox and Chromium or Save as ...)
https://www.fastenal.com/content/feds/pdf/Article%20-%20Galling.pdf


How To Stop Thread Galling On Stainless Fasteners
http://www.atlanticfasteners.com/tech-tips/how-to-stop-thread-galling-on-stainless-fasteners/


Thread Galling - What is Thread Galling?
https://www.boltdepot.com/fastener-information/materials-and-grades/Thread-galling.aspx


TECHNICAL BULLETIN - Galling of Stainless Steel Fasteners
http://www.pencomsf.com/wp-content/uploads/2012/08/galling_stainless_steel_fasteners.pdf

Thread galling is SO galling! Ha-hA!

Hope that helps you. Thank you.

Happy Hot and Humid Summery Hollow-Dayze!

Yet the cGMP manufacturing facility is aseptic and well air conditioned! Hope for no more nuts and bolts! Were makin' and packin' useful therapies when those that need it need it now! (I merely doc and illustrate the process. Hope to walk to work as the norm soon. Volvos need work!)

Iced Tea with (lot's o') Lemon MacDuffed (Unsweetened)
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Give your brickboard.com a big thumbs up! Way up! - Roger Ebert.

Randy,

Are you talking about SS bolts screwed into SS nuts, or SS bolts screwed into Al or ferrous metals?
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Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (getting ever closer to road worthiness)

Referring to applications where both the nut and bolt are both stainless steel.

Randy