Headset spanners – sizes 32, 36 and 40mm. Flat, thin open-end spanners designed for adjusting the threaded headsets. Normally these spanners are used in pairs: one spanner to keep the adjustable cup (with bearing race) fixed and the other to tighten / anchor the lock-nut against the adjustable cup. The spanners are also available in other sizes: 30, 31, 33, 35mm etc. This type of spanner can also be used for tightening the fixed cup of the open type bottom brackets.
