Square Taper BB Specs

JIS

'Japanese Industry Standard'

Shimano & Asia

2 degree taper

"Although both use the same two degree taper, the main difference is in the actual length of the taper, the JIS version is slightly longer, so if you try and put a crank designed for a JIS BB onto an ISO shorter tapered BB (like a Shimano Chainset onto a Campagnolo BB), then the crank may go to far up to the end of the taper."

ISO

Campangnolo & Europe