If you live in a bigger city, there should be a Fastener supply store that carries all varieties of nute, bolts, washers, etc. Bring one of the bolts with you is the easiest thing to do. I have also had some success in the fastener section in Home Depot and the like, YMMV. Usually you have to buy in bulk but 10 bolts will be a couple dollars. Or if you want something a little fancier, you could get titanium bolts from somewhere like http://torontocycles.com/

There is nothing special about most bike fasteners. Many places sell metric fasteners both at retail and online... McMaster-Carr (http://www.mcmaster.com) is probably one of the more well known ones in North America.

Otherwise go to your local hardware store and check out their fastener aisle. Quite a few places have metric fasteners available in small quantities.

Note that stainless bolts are not as strong as most black oxide coated bolts, and are also more prone to galling (cold-welding) on installation or removal. So, while it might seem like a good idea to avoid corrosion issues by "upgrading" to stainless bolts, that is not necessarily true. Test the other bolts (or the broken one) with a magnet. If the bolt is attracted to the magnet, then it is a high strength steel bolt and not the garden variety stainless.

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Less is more.

Most local hardware stores will have what you need.

Take the opportunity to get a new set in stainless steel. The weightweenies will be mortified, but you won’t have to worry about them rusting our on you from trainer sessions.

Not nearly as hard to find bolts like these now days. Places like ACE hardware are now serviced by venders who supply a huge variety of what were once rare nuts and bolts. Take the correct bolt with you and check it and the new purchase against the same (matching) nut to make sure the thread and pitch are the same. I've always used black bolts with a touch of grease to prevent seizing and rusting -never had a problem.

Most stems take M5-16mm screws (specialized might be different though). You can easily get a small lot of these on eBay.

https://www.ebay.com/...t=0&LH_PrefLoc=1

I always go with stainless, just to avoid the corrosion issues from sport drinks and sweat.

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ECMGN Therapy Silicon Valley:
Depression, Neurocognitive problems, Dementias (Testing and Evaluation), Trauma and PTSD, Traumatic Brain Injury (TBI)

As others have said, your local hardware store should have what you need. Personally I prefer Ace.

I replaced my stem and aerobar due to corroded bolts a year ago, ran into the same problem you did with finding bolts.

I will definitely add that the VAST majority of forum posts about this topic are utterly unhelpful! Everyone seems to say 'it's easy, just go to the online or local store, buy a matching bolt, the-end", but when you go online or locally there are soooo many different choices of lengths, threads, materials, etc. - I couldn't even figure out where to start on Mcmaster Carr!

I think I ended up buying quite a few various steel and stainless bike bolts none of which really fit well (too long, too shorts, threads not right) before I found one that actually worked, and then I went and rebought the same size ones in Titanium on Amazon.

I wish I could give you an exact link to what you should buy, but I was surprised at how little help the forums were for steering me toward the one I needed. There must be small variations in the types and sizes of bolts needed that makes it harder than it seems (I'm surprised that even your LBS couldn't help you here!)

hardware store man. It will be a hell of a lot cheaper there in the first place.

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Thanks for all the replies! I've found the thread type itself is not the issue it's the shape of the head and width. Many bolts come with a little collar on the head making it a bit wider (almost like a built in washer) but the Specialized real stem bolts don't. I'll try my local Lowe's and see what they have. Cheers everyone

mcmaster.com
grainer.com
mscdirect.com

Use Lowes or HD to get your thread pitch, note the length and bolt head type.

If one of those places doesn't have it, you don't need it. No company selling bikes is manufacturing their own fasteners for stems, bottle cages, or common items. It's from some huge industrial catalog. Sure, the Amazon/Ebay bicycle bolts might be wrong for your application. But they exist.

You can easily find metric fasteners online, including titanium ones if you want. Typically, you're stem bolts are m4 x .8 x (length), or maybe an m5x1.0 x (length), and the head type is commonly known as SHCS (socket head cap screw). Measurements mean: m4 is the bolt shaft diameter, .8 is the thread pitch, and the last # is the bolt length in mm. There are various bolt head types, but SHCS is most common on bikes.

You can google search "m5 shcs" or "m5 bolts", etc and find online retailers that will have what you're looking for

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Team Zoot-Texas, and Pickle Juice

My personal advice if you don't know what your looking at is to go to a small engineering shop.

They are much more likely to identify your bolts correctly (including if they are high tensile or not) and have suitable replacements available that might only cost a few beer tokens.

Some things to be aware of that may / may not be applicable to your bike :

1. A good proportion of stems use bolts with a slightly undersized head i.e. Not something you might find 'off the shelf'.

2. Most companies will over specify critical bolts - I guess for fear from failure / law suits etc. It's not uncommon to find 12.9 grade in stems and steat post heads etc.

3. As a general rule of thumb, if you are replacing 8.8 grade (the start of what's generally termed as high tensile) you should be ok to go with A2 grade stainless. A4 grade is a touch stronger. Ti should also be OK.

4. Use anti seize on the threads, especially if replacing with stainless or Ti in an ally base material.

If you inspect the existing bolt heads you may find some of the grades I have mentioned above forged into them. Non metric bolts use a different coding system to the above but I would be very surprised if you find non metric on a modern proprietary bike part.

If you can correctly identify the bolts you need and want a bit of bling, check out 'Toronto Cycles' ... ;-) You will also find they sell the reduced size bolt heads including the option of captive washers etc (if needed).

Hope you get sorted :-)

WD :-)

I will second McMaster, exceptional reasource for bolts etc. I have used them for home projects, work, and cycling. I needed a replacement bolt for my specialized basebar and it was going to cost 60 bucks for the bolt kit. Found the same bolt for less than 3 dollars. Most cycling companies use metric threading, so M1, M2 etc. This can often be confired at a local hardward store/lowes/homedepot which will have a thread finder jig to fit your bolt into. At this point you just need to know total length and head type.

M4 standard pitch is 0.7
M5 standard pitch is 0.8
(M6 standard pitch is 1.0)

Just want to clear that up for everyone used to American Freedom Units instead of Metric.

Side note: rear derailleur hangers and axles use M10 x 1.0 (fine pitch) instead of the more common M10 x 1.5

I'd call or email the stem manufacturer and ask them exactly what kind of bolt it is. I had the same problem, emailed Bontrager and they let me know. It made it much easier to order as others have pointed out, there are about a zillion types of bolts out there.

I'll just stick in my 2 cents worth while we're on the topic...

Be aware that stainless steel is also susceptible to 'other' forms of corrosion, particularly as a result of high chlorides - yes, thats right, the salt in your sweat (and sea water). Metallurgy nerds need not read on, but for the rest of us folk:

https://www.nace.org/...sion-Cracking-(SCC)/

I went through and changed all bolts to stainless a few years back, and have had 2 seat bolts and a stem bolt all fail within a short period of time. My advice would be to every so often, ditch them and put new ones in - its a small price to pay.

Don't get caught 30ks from home with a saddle that slips to its lowest position... like me.

MattyK,
Yep, you are correct. I was in error, and now see that I was off by a size and pitch relationship. Good catch.

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Team Zoot-Texas, and Pickle Juice

I went to my local Fastenal store. They have pretty much any standard or metric bolt you need. Bought 4 stainless bolts for my 3T Brezza Limited II risers for a couple bucks. Brought one in & they measured it & ordered it--came the next day to the store. www fastenal dot com (should allow you to browse the inventory). Variety of metals & they were awesome.

3T said they "can't" send me just the bolts, because they were all in riser kits & they would have to tear one apart just for bolts. That was an email directly from them (Italy). It took weeks for them to get back to me. The cost would have been absurd through the bike shop as well--they suggest the above place for quick replacement of the same bolt so I didn't have to order & wait for even a week (it'd take the shop at an astronomical higher cost, to get the bolts while I was out of riser pads). For a manufacturer to say they don't have replacement bolts for their product such as a couple bolts, without the entire kit, just screams B.S. Figured at least the US Distributorship would have some but they said no.

 



I face palm at your comments above. Bolt size listings are a google click away. I realize that not everyone dirty's the Machinery's Handbook bolt pages, but bolts are not that hard to figure out. Measure diameter, measure length, measure the pitch, go to a chart and determine what the threads are, buy bolts. This is a triathlon forum, not a forum for bolts and hardware for something that should have been taught in HS shop class. end rant

My two cents for posterity -

While it may be true that metric hex socket screws are easy to find in the good ol' US of A, here up in the grim cold of Soviet Canuckistan things are different. I have noticed that hardware stores are scaling back their inventory of fasteners and most won't have any hex socket screws anymore, and if they do they're SAE, not metric. While I detest Lowe's as a general hardware store, they used to carry a good selection of metric bolts, but no more. Home Depot, same thing. Rona was bought by Lowe's, so no luck there. Home Hardware didn't have any to begin with. And while I don't live in a major metropolis, there are half a million people around here.

I recently went to my local Brafasco and ordered a whole whackload of M5 and M6 bolts in various lengths. That solved my problem.

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Citizen of the world, former drunkard. Resident Traumatic Brain Injury advocate.

Try this

https://www.amazon.com/...olts/b?node=16403521