Purchased component
Commutator (hook type)
✓ Expert reviewed All content on this page has been reviewed by a senior motor engineer.
Process flow
Upstream manufacturing of this bought-in item is not covered yet; see the incoming inspection and approval tests.
Incoming inspection & approval tests
- Spin (burst) test at temperatureTypically 1.2–1.5 × maximum speed at elevated temperature; segment lift within limit
- Bar-to-bar and bar-to-bore insulationHipot per drawing
- Dimensions and runoutOD, bore, hook position; per drawing
- Copper gradeMaterial certificate (copper or silver-bearing copper)
Buyer FAQ
- Hook-type or slot-type commutator?
- Hook-type commutators are standard for small motors with fused (hot-staked) wire connections. Slot-type (riser) commutators are used where wires are soldered or welded into slots, usually on larger armatures.
- What tests prove commutator quality?
- Over-speed (spin) testing at elevated temperature for bar lift, bar-to-bar and bar-to-shaft insulation (hipot), and dimensional checks of the hooks and outside diameter.
- What copper is used?
- Hard-drawn copper, with silver-bearing copper for higher temperature and longer life. The bars are moulded into phenolic or other thermoset resin.