Chrome v Stainless Steel bolts

[User]

 

[gbb]

Stainless should be far stronger and will not corrode.
Chrome (plated) will deterioate with use and will probably still corrode (although very slowly)...and may more prone to snapping.
Stainless is probably marginally heavier than plated steel bolts.
The socket head in stainless will be infinately stronger than most plated bolts.

I'd go stainless every time (although i've access to hundreds of the bloomin things, so availaabilitys no problem)

 

[PpPete]

Hate to disagree but most stainless usually somewhat softer than good quality carbon steel (whether chrome plated or not). Not too many bike bolts made from expensive precipitation hardening stainless (you want to spend that sort of money then go titanium)

That said the corrosion resistance advantage of ordinary stainless is such that I go stainless every time too.

 

[gbb]

Hmm...i cant quote any technical stats, but as an engineer who's used probably thousands of bolts, i cant ever remember rounding the hex socket on a stainless bolt with an allen key, or sheared any either.
But i've ruined quite a few mild steel bolts

On the other side...and i'm talking heavy bolts under heavy stress....if a stainless bolt does shear through stress (on forklifts etc)...stainless is a bugger to drill and extract.

Bear in mind, on a bike, you will invariably be putting a bolt into alloy. The alloy will give long long before the steel (stainless or mild) bolt will.

 

[gbb]

Hate to disagree but most stainless usually somewhat softer than good quality carbon steel (whether chrome plated or not). Not too many bike bolts made from expensive precipitation hardening stainless (you want to spend that sort of money then go titanium)

That said the corrosion resistance advantage of ordinary stainless is such that I go stainless every time too.

Missed that point....and the point is, if you look at most bolts available to joe public...they're not good quality carbon steel.

 

[02GF74]

don't have the data to hand but stainles is about 6 ish but steel being 8.8 and avaialble up to 12.8 tensile strenght, whatever the units are.

look at the most highly stressed botls on bikes - for example the one for the stem clamp or seat post clamp - these are 12.8; never seen these parts come with stainless steel bolts.

 

[gbb]

I guess there's a case for absolute safety...and i mean absolute.

Ok, look at it this way. You want to replace your stem bolts. You go to a LBS and ask for some bolts. Do LBS carry the absolute correct grade bolts for that job....or do you end up with 'ordinary' plated bolts.

Perhaps i'm being too cynical. There are billions of crap and 'ok' quality mild steel bolts out there...unless i absolutely knew the ones i was getting are the right ones...i'd still stick with stainless.

That said, there's a right and proper time to fit the correct bolts for safety....OP didnt state what the bolts were intended for...mudguards perhaps

 

[02GF74]

using stainless for bottle cages it ok too. use them for disc calipers and not had one break so far.

 

[Proto]

Hmm...i cant quote any technical stats, but as an engineer who's used probably thousands of bolts, i cant ever remember rounding the hex socket on a stainless bolt with an allen key, or sheared any either.
But i've ruined quite a few mild steel bolts

On the other side...and i'm talking heavy bolts under heavy stress....if a stainless bolt does shear through stress (on forklifts etc)...stainless is a bugger to drill and extract.

Bear in mind, on a bike, you will invariably be putting a bolt into alloy. The alloy will give long long before the steel (stainless or mild) bolt will.

Depends on the stainless bolt. Most 'common or garden' stainless bolts (A2 grade) are very soft in comparison to typical engineering socket cap screws/bolts. Hex heads and hex sockets are very easily chewed up.
Further, there is a problem (a small one only for bicycles) of galvanic corrosion between stainlees steels and aluminium.

Having said that, I use stainless bolts at every opportunity on my bike.

 

[gbb]

Depends on the stainless bolt. Most 'common or garden' stainless bolts (A2 grade) are very soft in comparison to typical engineering socket cap screws/bolts. Hex heads and hex sockets are very easily chewed up.
Further, there is a problem (a small one only for bicycles) of galvanic corrosion between stainlees steels and aluminium.

Having said that, I use stainless bolts at every opportunity on my bike.

I dont know what to make of this thread.
Ive been in engineering, one way and another for 30 years. 'Common or garden stainless is indeed A2...A4 being better, but not generally used for 'normal' jobs, based simply on price.
Ive purchased tens of thousands of stainless and mild steel bolts for a team of engineers (high tensile usually..not the crap you see in DIY shops etc) , done up and undone countless bolts myself in the last 9 years particually...and ive rarely seen the head of a stainless bolt get chewed up...hexagon head or socket cap.
Where it does happen is on countersunk bolts. There's a lot of surface area between the bolt head and material being fixed..and because its countersunk, the socket for the allen key is smaller...therefore its easier to chew the hexagon. C/sunk bolts, i nearly always replace every time i undo them for this reason.
I replace my (good quality) allen key set about every 3 months..thats how many bolts i do and undo.
Mild steel, while less brittle than stainless does chew up...particually if the bolts are of dubious quality....

The only time i've seen stainless bolts shear is when under continuous stress, like on fork lift carriage backrests. This does indicate they dont like 'pulling' stress...but i'm talking very sever stress. But then the truth is, when you fit high tensile bolts, they shear as well.

C'mon Mickle, Spandex et al...if i go to a LBS and ask for some 5x20 bolts for my stem...would the bolts you supply be any different from a 5x20 you'd supply for a bottle cage.

I am a cynic...but ive fitted enough bolts to know i'd rather fit 'normal' stainless than 'normal' steel.

 

[Proto]

I replace my (good quality) allen key set about every 3 months..

This is a very good point. A worn allen key will wreck any bolt. Very quickly.

I've seen plenty of stainless socket caps with buggered up heads, but usually in application where they are frequently undone and re-tightened, for adjustemnt purposes for example.

Regarding shearing, I've never broken one, stainless or otherwise, and if anyone has then they have probably been hamfisted.

My 2%

PS gbb, only 30 years? Pah, just a kid!

 

[gbb]

This is a very good point. A worn allen key will wreck any bolt. Very quickly.

I've seen plenty of stainless socket caps with buggered up heads, but usually in application where they are frequently undone and re-tightened, for adjustemnt purposes for example.

Regarding shearing, I've never broken one, stainless or otherwise, and if anyone has then they have probably been hamfisted.

My 2%

PS gbb, only 30 years? Pah, just a kid!

 

[jimboalee]

For bottle cages, mudguards and lamp straps, use plastic bolts.
Glass filled nylon does the job.

 

[gbb]

For bottle cages, mudguards and lamp straps, use plastic bolts.
Glass filled nylon does the job.

Interesting ...
Is that for weight saving ? I've used hex head nylon bolts in industry, but never seen allen head nylon bolts.

 

[llllllll]

Further, there is a problem (a small one only for bicycles) of galvanic corrosion between stainlees steels and aluminium.

I had problem with that recently on my seat clamp. I'm sure I greased the bolt (A4 stainless), but I suppose it gets all the water and road cr@p from the back wheel. It was in there untouched for years, until I dropped my bike and needed to adjust the saddle. The bolt was absolutley solid, tried everything I could think of, but eventually had to resort to brute force and the threaded section still didn't budge, the head sheared off though.

Still using stainless though, just greasing more regularly.