Purchased component
Oil-impregnated Sintered Bushing
✓ 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
- Bore size and roundness after press-fitPer drawing; pin gauge after pressing into the housing
- Oil contentWeighing method per ISO 2795 / MPIF 57 (typically ≥ 18 vol%)
- Radial crushing strengthISO 2739
- Material and densityBronze or iron-copper per drawing; density per material code
Buyer FAQ
- How do oil-impregnated bushings work?
- The porous sintered bronze or iron is filled with oil (typically 18–25 % by volume). When the shaft turns, heat and pressure draw oil to the surface; at rest, capillary action pulls it back.
- Bronze or iron-based?
- Bronze runs quieter and suits higher speeds; iron-based (often with copper) is cheaper and stronger for lower speeds and higher loads. Iron-copper blends are common in small appliance motors.
- What causes bushing failures?
- Loss of oil from overheating, a bore that closes up after press-fitting, shaft misalignment and a rough shaft surface. Check the bore after pressing and keep shaft finish around Ra 0.2–0.4 µm.