Custom plain bearings
The demand for custom non-standard plain bearings is increasing. We can manufacture copper alloy materials to meet China’s national standards as well as the ASTM (UNS, SAE), EU, and JIS standards.
Bespoke plain bearings
viiplus collaborates with customers to find tailored solutions, offering plain bearings in various materials, sizes, tolerances, and designs.
Timely Delivery
Committed to meeting tight deadlines without compromising on quality, we ensure reliable and efficient production timelines.
Versatility
Capable of handling both small-scale and high-volume orders, we provide seamless support for projects of any size. Additionally, we can develop custom copper alloy materials based on specific customer requirements and drawings.
Specialized in self lubricating bearing
A self lubricating bearing carries its lubricant inside the material, so it runs without oil lines, grease points, or relubrication schedules. VIIPLUS manufactures the full range of oilless bearings — graphite-embedded bronze, steel-backed PTFE composite, oilless bronze, and polymer — as maintenance free plain bearings for mining, machinery, molding, metallurgy, and new energy.
Eliminating the lubricant supply is the single biggest reliability win in harsh-duty rotating equipment. Below is the complete guide to how self lubricating plain bearings work, how the families compare, how to select one, and how to install it for a long, grease-free life.
Custom Machined Bronze Parts & Bearings
What Are Self-Lubricating Bearings?
A solid lubrication bearing integrates the lubricant into the structure. In graphite-embedded designs, plugs of solid lubricant sit in holes across the sliding surface and transfer a thin film to the shaft as it moves. In PTFE composites, a low-friction liner does the sliding directly. Either way, the bearing is maintenance free by design — no external oil reaches the contact zone because none is needed.
The payoff is not just “no grease nipple.” A maintenance free plain bearing removes an entire class of failure: missed lubrication, contaminated lube, and lube that cannot survive the temperature. It also removes the labor and downtime of service intervals, and it keeps the surrounding equipment clean. For original equipment manufacturers this means a longer warranty-grade life; for plant operators it means one less thing to schedule and forget.
For equipment designers this shifts risk from the field to the spec sheet: the bearing is qualified once, at the design stage, instead of relying on a maintenance crew to lubricate correctly for years. That is especially valuable in exported or remote equipment, where the first missed service interval would otherwise end in a seized joint. Specifying a self-lubricating type moves the reliability guarantee into the component itself.
Oilless Bushing Material, Machining Parts
Types of Self-Lubricating Bearings
Types of Self-Lubricating Bearings
- Graphite-embedded (JDB) — bronze/brass base with graphite plugs; heavy load, high temp, oilless.
- Steel-backed PTFE composite (PTFE/POM) — thin, very low friction, dry or lightly greased.
- Oilless bronze — porous or plug-lubricated bronze for moderate duty without oil lines.
- Polymer / engineered plastic — corrosion-proof, light, for clean or food-adjacent duty.
Each family occupies a different corner of the duty map. JDB takes the hottest, heaviest, dirtiest jobs; PTFE composite takes the fastest, lightest, most precision-sensitive ones; oilless bronze covers the middle; polymer covers corrosive or hygienic zones where metal is unwelcome. Picking the family is therefore the single most important decision — the rest is sizing and fit, which we handle from your drawing or duty cycle.
Self-Lubricating vs Standard Bearings
| Aspect | Self-lubricating | Standard oil/grease |
|---|---|---|
| Maintenance | None (oilless) | Relubrication schedule |
| Contamination risk | Low (no grease) | Grease attracts grit |
| High-temp suitability | Graphite type excels | Oil breaks down |
| Life driver | PV, shaft hardness | Relubrication discipline |
The trade is simplicity versus ultimate load. A standard grease bearing can carry very high loads if maintained perfectly; a self-lubricating bearing carries a defined, often lower load but does so with zero attention. For most modern equipment the second property is worth more, because “perfect maintenance” is rarely achieved in the field.
Material Selection Guide
| Material | Load | Speed | Temp | Pick when… |
|---|---|---|---|---|
| Bronze + graphite | Very high | Low–med | ~300–400°C | Heavy, hot, dirty |
| Steel-backed PTFE | Medium | High | ~200°C cont. | Fast, light, precise |
| Oilless bronze | High | Medium | Moderate | General oilless duty |
| Polymer | Low–med | Medium | Low–med | Corrosive/clean zones |
Read the table as a map, not a ranking. Start from temperature: if it exceeds ~200°C continuous, only graphite bronze qualifies. Then speed: if it is high and load low, PTFE composite wins. Then load: if it is very high, graphite bronze or oilless bronze. Environment (dust, water, corrosion) then tips the final choice. When two families look viable, we usually recommend the one with the larger margin on your limiting parameter.
How to Choose the Right Bearing (5 Steps)
- Define the duty — radial or thrust, load, speed, temperature, environment.
- Pick the family — graphite bronze for heavy/hot, PTFE composite for fast/light.
- Select material & size — standard series or special dimension.
- Confirm shaft — hardened (≥45 HRC) and smoothly finished for film formation.
- Verify with our sizing logic — check PV against the rating before ordering.
Two notes make the process reliable. First, never skip shaft hardness — a soft shaft will dent or gall even the best bushing, so the ≥45 HRC rule is a prerequisite, not a nice-to-have. Second, treat the PV check as a hard gate: if your duty exceeds the rated PV, either step up the material (e.g., JDB instead of PTFE) or change the geometry to spread load. Guessing here is the most common cause of early oilless-bearing failures we see in returned samples.
Installation & Maintenance
Install as a press fit into a finished housing bore, keeping the bore true and protecting any graphite plugs during insertion. For oilless types there is no lubrication step — just keep the shaft clean at first run to seat the transfer film. Because there is no grease, housings stay clean, which is a major advantage in food, textile, and cleanroom duty.
Shaft preparation decides whether you get the rated life. Harden the shaft (typically ≥45 HRC), grind it smooth, and avoid sharp entry chamfers that could shear a graphite plug on insertion. Press squarely with a proper mandrel rather than driving one edge. Should a bearing ever need removal, extract axially rather than prying, to protect the housing bore for the replacement. These small steps are the difference between a bearing that lasts and one that fails early for avoidable reasons.
type of Custom Bearings & Bushings, Flanged Bearings, Custom Oilless Bronze Bushings, Custom Sliding Bearing
Custom Bearings & Bushings Materials & Alloys We Machine
Applications by Industry
- Mining & quarrying — crushers, conveyors, vibrating equipment in dust and water.
- Construction & earthmoving — pivots and linkages under shock load.
- Injection molding & die-casting — hot, cyclic, grease-hostile plates.
- Metallurgy — continuous casters, furnaces, kiln cars.
- New energy — solar trackers, wind, and battery-line motion components.
The through-line is harsh or inaccessible duty: dust, heat, water, or simply no technician to grease the joint. In those conditions a self lubricating plain bearing is not a premium option but the only one that reliably reaches the machine’s design life. We routinely see oilless bearings outlast the equipment around them, which reframes them from a cost line to a reliability investment.
The umbrella takeaway is simple: match the self-lubricating family to the limiting duty — heat, load, or speed — and the bearing will look after itself. Everything else, from fit to shaft prep, is supporting detail. Get that one choice right and the rest follows; get it wrong and no amount of maintenance will save the joint.
Material Selection
Bronze Alloy Composition
Casting
Centrifugal casting, continuous casting
Machining
Precision Machining
Quality Inspection
Material Testing, Surface Inspection
