# Rotor bolt size?



## Nim (Jan 2, 2004)

Are disc brake rotor bolts a standard size? If so what size?


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## Uzzi (Oct 28, 2003)

Nim said:


> Are disc brake rotor bolts a standard size? If so what size?


I would say M5 but would not be suprised if there would be other sizes around. Anyway the ones that are on my bikes are all M5...


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## applegreenheckler (Feb 26, 2005)

they should be m5 but most have a t25 head on them. Any good bike shop should have them


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## kjmccarx (Apr 3, 2014)

applegreenheckler said:


> they should be m5


Does anyone know what the thread pitch on them is? I would like to order some hex head replacements from McMaster or something.

EDIT: Looking at McMaster it seems like the only M5 bolts are M5x0.8


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## SlowJoeCrow (Mar 16, 2009)

Bear in mind that stock rotor bolts include factory applied thread locking compound, since having a rotor bolt vibrate loose while riding could very unpleasant. 
If you go with generic bolts you'll need Loctite or similar.


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## kjmccarx (Apr 3, 2014)

SlowJoeCrow said:


> If you go with generic bolts you'll need Loctite or similar.


I do have loctite, but that's a good heads-up for people buying their own bolts.

At McMaster you can buy bolts with threadlocker on them already... but they are overpriced.


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## matt4x4 (Dec 21, 2013)

Looking around for bolt size, I figured M5, but what is the length.
Bolt Supply House is where I am going.

edit - Looks like they are M5 x 10mm


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## Mr Pig (Jun 25, 2008)

Stick with the torques head. You do get Allan head ones but they tend to round too easily. Also stick with steel. You get aluminium and titanium bolts but I've had the heads on those crack!

The blue locktite that comes on many bolts isn't essential. There is no ways I'd bother trying to find compatible bolts from an industrial supplier. Plenty of bolts sold specifically for the job and not expensive so it's a fool's errand.


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