Zinc plated rivet versus AISI 201 HT or 301 1/2 Hard 2

[trainguy]

Gentlemen,

I'm toying with the use of Alcoa Huck BOM rivets to connect stainless steel railcar sideframes.

The SS is either AISI 201 HT (original) or 301 1/2 Hard (new repair components).

All these fasteners will be hidden under non-structural moulding, but it's not guaranteed they'll stay dry.

Any thoughts?

Thanks in advance,

tg

 

[EdStainless]

When they get wet the rivets will suffer accelerated corrosion.
Can you accept the results?

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Plymouth Tube

 

[trainguy]

Ed,

That was quick!

Will this accelerated corrosion weaken the rivet over time, or is it only a surface phenomenon?

I can accept a corroded "looking" fastener, but not a weakened one.

tg

 

[mcguire]

Not good. You are compromising a major structure for a trivial component, and it IS compromised.

Michael McGuire

http://stainlesssteelforengineers.blogspot.com/

 

[trainguy]

Nothing trivial about it. The structural fasteners are to be hidden under moulding, they're not holding it up.

I have serious tool access issues related to using 2 piece stainless steel rivets. The alternative here is then to use stainless steel hex head bolts. What is an acceptable method of preventing loosening (for the next 30 yrs) for these types of bolts?

Loc-tite?
SS nuts with nylon inserts?
Both?

The other possibility is the dreaded stainless steel Magna-Lok, but it's not as robust as I would like.

Thanks again...
tg

 

[TVP]

A few quick thoughts. First, have you contacted Huck or Avdel to discuss making a high strength stainless steel version of the Huck BOM or Avibulb/Avinox? If there is sufficient quantity, they may be able to offer you something in a standard size but with a non-standard, high strength stainless steel. Second, is there any way that you can redesign the joint area so that the fasteners will not be exposed to water, etc.? This is not the ideal solution, but may be something to consider. Third, have you looked at any of the aerospace fasteners, such as Huck-Clinch or MS blind bolts? Obviously more expensive, but they may be a better option than hex head bolts, redesigned parts, etc. Here are links to the relevant AFS pages for these fasteners:

http://www.alcoa.com/fastening_systems/aerospace/catalog/pdf/specifications/BBCatalog-9-2000.pdf

http://www.alcoa.com/fastening_syst...ifications/AFSBlindFastenerProcess Manual.pdf

Regarding vibration loosening of conventionally threaded fasteners, this kind of application would need first and foremost a high level of clamp load, with possibly one of the useful additional features such as thread adhesive. Nuts with a nylon prevailing torque feature will not provide much benefit here, nor will any of the conventional lock washers, serrated heads, etc. You might want to investigate the proprietary lockwasher from NORD-LOCK:

http://www.nord-lock.com/

 

[btrueblood]

Stainless versions of the huck pull-rivet exist. See the links TVP posted, or another supplier would be:

http://www.cherryaerospace.com/product/blindbolts.html

 

[EdStainless]

They will come loose.
Weld. Spot welding of high strength cold worked SS is a common practice.

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Plymouth Tube