BB axle bolt size
BB axle bolt size
Is a square taper bb axle bolt thread 8 mm standard on ShImano un52 or like?
Re: BB axle bolt size
It looks like M8 metric fine x 15mm long (1mm pitch thread) on this bolt from a UN55, with a 14mm across flats bolt head c/w built in washer (19.5mm diameter).
M8 coarse hex bolt in picture is 1.25 mm pitch, 13mm across flats.
Pictures over 10mm to count the threads
Link to thread standards chart
https://www.carrlane.com/engineering-re ... -standards
M8 coarse hex bolt in picture is 1.25 mm pitch, 13mm across flats.
Link to thread standards chart
https://www.carrlane.com/engineering-re ... -standards
Last edited by colin54 on 4 Jul 2022, 12:01pm, edited 1 time in total.
Nu-Fogey
-
axel_knutt
- Posts: 2928
- Joined: 11 Jan 2007, 12:20pm
Re: BB axle bolt size
Yes, it is.
I made the mistake of buying coarse ones first when I was looking for bolts to hold a BB tool on.
“I'm not upset that you lied to me, I'm upset that from now on I can't believe you.”
― Friedrich Nietzsche
― Friedrich Nietzsche
Re: BB axle bolt size
The bolt head is 14mm across flats, not 15mm, I've edited my initial post.
Nu-Fogey
Re: BB axle bolt size
Thanks very much for such prompt replies .