The Starrett 463 Micrometer Head features lock nut, 0-1/2" range, .001" graduation, lock nut, and carbide face. 0-1/2" Range, .001" Grad, Lock Nut, Carbide Face.
The Starrett 463 and 1463 Micrometer Head features 0-13mm range, 0.002mm graduation, ratchet stop, and lock nut. 0-13mm Range, 0.002mm Grad, Ratchet Stop, Lock Nut. Carbide Contacts.