Chainring bolts don't get much attention until one strips or goes missing mid-repair, which is usually when you find out how specific Shimano's fastener catalog really is. The Shimano FC-M970 Inner Chainring Bolt Set covers a surprisingly wide range of cranks for a part originally spec'd on an XTR mountain crank — the same M8 x 10.1mm bolt fastens the inner ring on modern Dura-Ace and Ultegra road cranksets. If you're doing a chainring swap on an 11-speed or 12-speed Shimano road crank, this is the factory replacement hardware.

The set includes four bolts finished in black anodizing to match the factory look. Each bolt uses a Torx T30 interface rather than a hex, which resists cam-out when you're working through the torque range and keeps the head clean if you ever need to service the ring again. The bolts thread directly into receivers machined into the crank arm or spider, so there's no separate nut on the backside to hold with a second tool.

Confirmed compatibility covers the inner ring position on XTR FC-M970 and FC-M980 mountain cranks along with Dura-Ace FC-9000, FC-9100, and FC-9200 and Ultegra FC-6800, FC-R8000, and FC-R8100 road cranksets. Shimano lists a torque specification in the 12-14 Nm range for these fasteners — worth checking the specific service manual for your crank before final tightening, because a few reviewers have reported snapping bolts by going higher than needed. A Torx T30 driver with a torque wrench is the right tool for the job.