Pros and cons of stainless steel nut and bolt kits?

[Allan.Atherton]

Everybody uses them and I really don't know of any cons.
http://www.theboltguy.com/index.htm
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[tricyclerob]

I used stainless on my R69, but I was not going for absolutely correct restoration. I ground the markings off the bolt heads then polished. They look great but for correctness I believe the fasteners shoud be cad.plated. Depends on what you are trying to do with your bike. If a bike is very original with good original paint and other finishes, I would go with the cad to maintain the originality, but if it needs lots of work, [as in a "bike in a box"] or was prev."restored" then I would go with whatever look you like. rj

[EuroIron]

cons

1) 300 series fasteners are not high tensile strength

they equate to about grade 3 in SAE or USS fasteners

some even seem to be grade 2 equivilant and no more than 30,000 psi tensile strength

this means if you are replacing a grade 8 equivalent axle or such with stainless

it needs to be quite a bit larger to preserve the original engineering

is that axle hardened 400 series? test it with a magnet but I would bet money against it, it would cost much more because 400 is more expensive to purchase, machine, and heat treat

is that axle 347 stainless or 2205 super duplex stainless?

again I doubt it as it would cost 5 times the going rate, or maybe more


2) stainless threads into steel threads will indeed gall without much provocation

make sure all threads are blasted/peened and then buffed with a stainless wire wheel as all it takes is one tiny burr or sliver to wreck your day

electrolysis also is a factor with dissimilar metals so I'll share my opinion that copper paste should always be used with stainless threads regardless of which metal they screw into but if you are screwing stainless into stainless or titanium..... and don't exercise all precautions........ the likelihood you will regret it...... becomes much higher

3) 300 series (food grade) will indeed rust IF it is in contact with ferrous metal or acid

it will rust if you blast or sand it with media that has been used on ferrous metal

read again about copper paste and this will greatly reduce this real phenomena

4) 300 series stainless will work harden although it cannot be heat treated

so for some fasteners that are subjected dynamic loads, most commonly shear types, they can harden and break

however, the first harmonic has proven to get the best of some over time

of course if you are using stainless fasteners as such

you should deem them as definitely having a life cycle and replace them after they have been subjected to reasonable number of loadings

that all being said, most all the bikes I build are done with stainless or ti fastnerss

I seldom ever use stainless axles because they are stupid

I don't use stainless steering stems for the same reason

my silver bobber has a 13mm front axle of Titanium

it's rear is hollow and 20mm of the same

that bike has been airborne more times than I can count

I promise if the axles were stainless

they would certainly be bent if not already broken


I have countless pix of stainless fasteners that just weren't quite up to snuff for their application

and a lowly autoparts store grade 5 would have been overkill

[keirn7373]

Since my R26 is a basket case with missing hardware and needs a ground up I'll go with stainless. I am planning to enjoy having this bike ridden by my son as well and not have it sitting just to look at so I guess the "purist" path is not the way. Thanks for your input.

[Allan.Atherton]

...... I seldom ever use stainless axles because they are stupid... I don't use stainless steering stems for the same reason... I promise if the axles were stainless... they would certainly be bent if not already broken... My stainless steel axles and steering damper from Mobile Tradition have been satisfactory for eight years. So have all the other stainless nuts and bolts. I do use anti-seize to protect against galling. The few nuts that are not stainless have rusted, and I hear that cad plating does not last very long, either.
I think the choice for most people is between a cheap kit for a runner, and an expensive kit for a restoration. The cheap one will have dull unpolished bolts with hardware markings, and the expensive one will have the markings ground off and the heads polished.
Cad is for winning shows, expensive as stainless, and it's hard to find a place that will do it. You need to have all the old fasteners on hand and in usable condition, or buy new ones, which may or may not be in cad.

[EuroIron]

that's great they are working and working well

assuming you properly thrash it and often

what that tells you is the original design was over engineered

the axles are very large as are the steering stems

try a 300 series stainless axle on say a HD 45 solo bike's front wheel

they are 1/2" and the bike pushes close to 500 pounds

even with good fitting and adequately large spacers

it won't last long

try one on a cush drive Norton Commando hub

recipe for disaster since the much stronger steel axles didn't hold up well

you don't have to take my word for it

just look up the specs on stainless and then compare to even flame harden-able grade steels

the biggest killer for many marginal stainless applications is that stainless is much more elastic and it will indeed work harden

but there are several other metals that will not rust and do posses much higher strength characteristics

just saying that most that is used by motorcycle enthusiasts is 300 series and not of high tensile strength

[VBMWMO]

Greetings all. I am restoring a basket case R26 and I am in the middle of the disassembly process. Before I begin the restoration I would like to hear the pros and cons of stainless kits for rebuild. Also, I cannot manage to separate the transmission from the engine block...any suggestions?

[oldchrome.atl]

Hi all,
I am new to the BMW restoration scene and wanted to see if there was any new thoughts about using stainless steel vs original steel (the original thread is over 4 years old).

I have a true basket case (1955 R69) that i want to return to the world. I am missing almost all the nuts and bolts. Is there a good source for the correct nuts and bolts?
I think that EuroIron brings up valid issues.
At the same time, I realize that many people have now had additional experience with the SS bolt kits.
Any new thoughts about what direction I should go?
Thanks!

[miller6997]

Your '55 R69 is a very special bike, and if it were mine to restore, I would just cut to the chase and ask the advice of Craig Vechorik (Benchmark Works) at (662) 465-6444. I know he sells stainless kits and I assume that he uses them on some of the bikes he works on, but he can surely set you straight on the pros and cons.

Several years ago I replaced most of my perfectly good original fasteners with stainless during a major detailing. Looking back, I don't know why I did it, and I probably would not do it again today. (I kept the originals and may some day hit another choice point on this issue.)

Jon

[R.D.Green]

This may be over-stating the obvious but for absolute concours correctness, the fasteners need to be period original, i.e., not just cad-plated but with the original markings on the bolt heads. I think a lot of this stuff was simply tossed out by owners in years past but it is now becoming increasingly rare and a lot of it is crazy expensive when you do find it. For example, I was following a pair of /2 Earles fork bolts on eBay a couple of months ago. They were original but needed re-plating. I was prepared to go, maybe, $50.00 for the pair. If I recall correctly, they sold for $112.00. I didn't want them that badly.