Bicycle Mechanics - Replace cap bolt and stem bolts

I'm a home mechanic and recently noticed how rusty the cap bolt and the bolts on the stem are.

I have a specilized tarmac with the specialized stem. I assume all the bolts are pretty standard? What material should i be looking for? Titanium sounded good, but i hear they can break even if they're torqued to spec which is worrying.

What do you recommend replacing with and where can i purchase them from? I have 3 bike i would like to purchase for.

Thanks,

Stainless steel.

Stainless steel.

+1

+2 SS sounds good.


Titanium sounded good, but i hear they can break even if they're torqued to spec which is worrying.


For the stem bolts I would not use something that might break, but for the top cap it doesn't matter what you use because it's not under any load once the stem is tightened.

Anyone know the exact bolt spec?

From my research I'm guessing it's the M5 0.8 18mm for the stem and probably a M5 0.8 30mm for the the cap?

Anyone know the exact bolt spec?

From my research I'm guessing it's the M5 0.8 18mm for the stem and probably a M5 0.8 30mm for the the cap?
That's probably right for some but I've seen many M6x1.0 - 30mm top cap bolts. I'd just take the bolts you have to a good industrial supply shop and have them matched but in stainless. Be aware that a lot of bolts used on bike parts have unusual head shapes and diameters so getting an exact match may be difficult.

The LHS (local hardware store) will most likely have what you need in stainless. Bring the screws down and match head/length and threads. I'm hoping standard hex socket head will fit your stem.