A car interior is full of bearings that are never lubricated, never adjusted and expected to work a million times — and most of them are moulded nylon. Automotive & Electric Vehicles duty is shock load, wide temperature swings and electrical erosion from the inverter; the material is what decides whether the bearing survives it.
| Industry duty | shock at the wheel end, 15,000 rpm in the e-drive, and inverter shaft voltages |
|---|---|
| Typical media | road spray, brake dust, gear oil, glycol |
| Housing temperature | −40 to +150 °C |
| Material and grade | PA66 nylon |
| Hardness | — (polymer, 75 Shore D) |
| Temperature ceiling | 105 °C |
| Corrosion / chemical | oils and greases; swells in water |
| Relative cost | 0.15× a steel bearing of a standard 52100 bearing |
Interior mechanisms are designed around cost and noise, not load. A glass-filled PA66 bush snaps into a stamped bracket, absorbs the tolerance stack of the trim assembly and runs dry for the life of the vehicle. The engineering work is the clearance: nylon grows about 0.5% between a dry January and a humid July, and a mechanism that ignores that will stick in summer.
| Position | Bearing type | Material / finish | Why it works there |
|---|---|---|---|
| Seat recliner pivot | PA66 bush | PA66 bush, glass filled, dry | High cycle at low load with no grease to stain trim. |
| Latch / handle pivot | PA66 bush | PA66 bush | Tough at −40 °C, so it does not fail brittle in a crash load. |
| HVAC blend door | PA66 bush | PA66 bush with PTFE | Quiet, low torque, tolerant of dust. |
| Material | Fit here | Choose it when |
|---|---|---|
| PA66 | Best fit | Interior pivots and bushes at low load, where cost per unit and NVH dominate. |
| POM | Workable alternative | Lower moisture pick-up and better dimensional stability for a precision flap. |
| Bronze | Workable alternative | Under-hood temperatures above 105 °C, where nylon softens. |
Usually a dry polymer against a plated or painted shaft, at very low speed. A PTFE-filled grade or a drop of PTFE-loaded grease at assembly fixes it.
Below 105 °C and away from fuel, yes. Above that, PEEK or a bronze bush.
It does the opposite over time — creep relaxes the fit. Use a knurl or a shoulder instead.
Hardness, temperature, corrosion and equivalents for PA66 nylon.
Read →Typical duty, recommended types and suffixes for automotive & ev.
Read →Wheel end & driveline — wheel hub pairs, gearbox shafts and e-drive rotors.
Read →Brake & road-spray — brake-adjacent mechanisms, exposed chassis joints and sensor bearings.
Read →Send the position, bore size, quantity and the medium it sees. We reply with the material certificate, clearance class, lubricant and price within 30 minutes on working days.