Washers for SS fasteners

[TpaRAF]

I am specing ASTM F593 Group 1 Alloy 304 bolts and ASTM F594 Group 1 Alloy 304 nuts. The nominal diametre is 3/4", and they are being used as anchor bolts for railing in a marine environment.

I cannot find an ASTM citation for standard or plate washers to use with these fasteners. Any ideas?

Thanks for your expertise!

 

[Metalguy]

Can't help with the washers, but why not use 316 instead of 304? Any salts/Cl in the water/air?

 

[CoryPad]

You can cite ASME B18.22.1 Plain Washers for dimensions. You would need to refer to something else for the material. Washers are best if they are strong and hard, so 304 & 316 are not totally appropriate.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[sdz]

It is best to use bolt and nut of different hardness so as to avoid galling.

"Galling can also be reduced by using two different stainless steels, of significantly different hardnesses, on the mating surfaces. A Brinell hardness difference of 50HB may overcome galling.

A common belief that the use of grade 316 studs with grade 304 nuts (or vice versa) will avoid galling is a myth (there is no notable difference in galling)."

http://www.assda.asn.au/asp/index.asp?pgid=18732

 

[rmw]

When mixing metallurgies in a marine environment, consider the galvanic couple that you will be creating, and try to pick materials that will mminimize the galvanic potential.

rmw

 

[unclesyd]

Plan ahead washers of all descriptions are still in short supply in quanities.

 

[Paskenell]

TpaRAF

You might consider the MS 15795 washer series. I am not aware of any ASTM stainless washer specs, but the above stainless steel washer military specification might be useful.

 

[TpaRAF]

Thanks to everyone for their input on this issue. I'll use the 316 alloy instead, since chlorides are definitely present.

I'm not sure galling will be an issue, as the fastener will not be removed frequently (if ever). I would use a harder stud than nut, if this is an issue -- but I'm trying to find relatively common fasteners for this application.

Regards, RAF

 

[MarkJ2]

I don't know if you already have your problem solved, but if not I would try contact Infinity Fasteners in Kansas City. They do a lot of stainless steel supply for the cooling tower industry and should be able to help