Solid lubricant bushings are bronze bearings with graphite or other solid lubricant plugs embedded in the bearing surface. They are specified when grease access is limited, contamination is likely, or the motion is slow enough that a conventional oil film is hard to maintain.
Graphite-plugged bronze bearing pages commonly position these parts for heavy load, low speed, intermittent motion, and elevated temperature. The bronze carries the load; the solid lubricant transfers a film to the shaft during movement.
| Quick spec | Catalog reference |
|---|---|
| Bearing type | Graphite-plugged or solid-lubricant bronze bushing |
| Common base alloys | C93200, C95400, C86300 |
| Lubricant pattern | Graphite plugs commonly cover part of the wear surface |
| Typical service | High load, low speed, hard-to-lubricate motion |
| Temperature reference often listed | Up to about 600°F depending on alloy and lubricant system |
| Size format | ID x OD x Length, plus plug pattern and groove details |
Manufacturing & Performance
The bearing is machined from cast bronze, then drilled or pocketed for solid lubricant plugs. During operation, the lubricant smears onto the mating shaft or plate and reduces metal-to-metal contact, especially during start-stop and oscillating motion.
This design is strongest where grease would wash out, burn off, attract dirt, or be difficult to apply. It is not a cure for poor shaft finish, severe misalignment, or undersized bearing area; load, speed, and contact pressure still need to be reviewed.
Standard Tolerances
Graphite-plugged bushings are usually machined to print. For sleeve-style plugged bearings, these cast bronze catalog tolerances are useful reference points before a final drawing review.
| Nominal size | ID tolerance | OD tolerance | Length tolerance | Concentricity |
|---|---|---|---|---|
| 3.000” and under | +/- .0010” | +.002” / +.003” | +/- .005” | .003” T.I.R. |
| Over 3.000” | +/- .0015” | +.003” / +.005” | +/- .005” | .003” T.I.R. |
| Plug pattern | Quote by drawing | Quote by drawing | Quote by drawing | Confirm edge distance and coverage |
Size & Availability
Solid lubricant bushings can be supplied as sleeves, flanged bushings, thrust washers, wear plates, or custom machined shapes. Specify ID x OD x length for bushings, or include the full drawing for plates and non-round components.
Alternative Alloys
- C95400 Aluminum Bronze for high strength with good general wear resistance.
- C86300 Manganese Bronze for severe low-speed load and shock.
- C93200 SAE 660 Bearing Bronze for general bearing bronze plugged parts.
- C95800 Marine Bronze for marine or corrosion-sensitive applications.
Typical Applications
- Construction equipment pivots, loader pins, excavator joints, and mining equipment.
- Mold and die wear plates, press components, and guide systems.
- Steel mills, paper mills, furnace equipment, conveyors, and chain systems.
- Marine deck equipment, cranes, winches, and outdoor mechanisms.
RFQ Details That Speed Up Quoting
Send alloy, ID, OD, length, quantity, shaft material, shaft finish, motion type, operating temperature, and whether you need a standard plug pattern or a print-specific layout.