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 JDB Graphite-Embedded Bearings
A JDB bearing is a solid-lubricant-embedded, truly oilless bearing: a high-strength bronze base with graphite plugs that lubricate the shaft as it moves. No oil lines, no relubrication, no downtime. VIIPLUS manufactures graphite bearings in JDB650 (CuZn25Al6Fe3Mn3) and lead-free grades for metallurgy, mining, and high-heat applications.
When equipment runs hot, dirty, or inaccessible, conventional oil-lubricated bushings fail — the lubricant carbonizes, washes out, or simply cannot be supplied. A graphite plugged bearing removes that failure mode entirely. Below is the full picture of how JDB graphite bronze bushings are built, rated, and applied, and how to specify one for your duty cycle.
Custom Machined Bronze Parts & Bearings
What Is a JDB Graphite Bearing?
JDB stands for a family of solid-lubricating bearings built on the same principle: a load-carrying metal matrix (bronze or brass) with holes drilled or cast into the sliding surface, then filled with graphite or a graphite-based solid lubricant. Under load and motion, a thin transfer film of graphite forms on the shaft, giving a low-friction, self-replenishing layer. The result is an oil free bearing that performs without any external lubricant.
Two common constructions exist: a single-alloy graphite plugged bearing (solid bronze with plugs) and a bimetal version with a steel backing plus a bronze layer carrying the plugs (higher strength, thinner wall). Both deliver the same oilless behavior; the choice depends on housing strength and wall thickness.
At a glance, the JDB approach gives maintenance and procurement three concrete wins: no scheduled lubrication (so no grease nipples, lube routes, or missed intervals), tolerance of the heat and contamination that destroy oil films, and a long, predictable life that makes spare-parts planning simple. Those are the reasons graphite-embedded bearings now appear from steel mills to food lines — and why they are usually the first oilless option we propose for heavy, hot, or dirty joints.
Conventional oil- or grease-lubricated bushings fail in three predictable ways that a JDB graphite bearing avoids: the lubricant carbonizes and forms varnish at high temperature; it washes out in water or solvent; and it attracts abrasive dust that turns the contact zone into a lapping compound. By contrast, the solid lubricant is part of the part itself — there is no external supply to break down, starve, or contaminate. That is why oil free bearings are specified for continuous-process equipment where an unplanned stoppage costs far more than the component.
Oilless Bushing Material, Machining Parts
JDB Material Grades
We work with the standard JDB grade families and can match customer-specified equivalents:
| Grade | Base Alloy | Character | Use |
|---|---|---|---|
| JDB650 | CuZn25Al6Fe3Mn3 (manganese bronze) | High strength, wear & corrosion resistant | Heavy load, high temp, general oilless |
| JDB300 | High-tensile brass (CuZn25Al5Mn4Fe3) | Hard, shock resistant | Machine components, heavy duty |
| JDB-FR | Steel-backed + bronze layer + graphite | Thin wall, high housing strength | Compact, high-load assemblies |
| JDB (lead-free) | Compliant CuZn / CuSn variants | RoHS/REACH friendly | Food, export, eco programs |
Oilless Bushings, Bronze Alloy Selection Matrix
The performance of an oilless bushing under high loads or corrosive environments relies entirely on its base alloy. Below is a structured guide to our commonly used bronze materials.
CuZn25Al5 (High-Strength Manganese Bronze) – The Industry Standard
This is the default and most widely specified base material for heavy-duty applications.
-
Key Traits: Excellent mechanical strength (Hardness 190–220 HB) and high static load capacity (up to 150 N/mm²).
-
Optimal Environment: General machinery, heavy construction equipment, and high-load/low-speed joints.
-
Standard Equivalent: ASTM B505 C86300 / EN 1982 CuZn25Al5Mn4Fe3-C.
CuAl10Ni (Nickel Aluminum Bronze) – The Extreme Environment Choice
Engineered for situations where standard brass or bronze would degrade.
-
Key Traits: Exceptional corrosion resistance and broad temperature tolerance (-200°C to +400°C). High resistance to shock loads.
-
Optimal Environment: Marine engineering, offshore platforms, chemical pumps, and high-temperature furnace mechanisms.
-
Standard Equivalent: ASTM B148 C95800 / EN 1982 CC333G.
CuSn12 / CuSn12Pb (Tin Bronze & Leaded Bronze) – The Balanced Performer
Often referred to as “gear bronze,” this alloy provides an excellent balance of wear resistance and smooth sliding properties.
-
Key Traits: Good anti-friction behavior, suitable for moderate speeds (up to 1.0 m/s), and resistant to fresh water and oils.
-
Optimal Environment: Turbines, medium-speed gearboxes, and general industrial automation.
-
Standard Equivalent: ASTM B427 C90800 / EN 1982 CC483K.
CuSn7ZnPb (RG7) – The Economical Alternative
A highly versatile, cost-effective alloy for standard conditions.
-
Key Traits: Adequate load capacity for light-to-medium duty applications with moderate corrosion resistance.
-
Optimal Environment: Automotive hinges, agricultural attachments, and general-purpose light-duty bearings.
-
Standard Equivalent: ASTM B505 C93200 (SAE 660) / EN 1982 CC493K.
type of Cylindrical Oilless Bronze Bushings, Flanged Oilless Bronze Bushings, Slide Plate
JDB vs PTFE Composite vs Bronze
JDB vs PTFE Composite vs Bronze
Three oilless or low-maintenance routes are often compared. Pick by duty, not by habit:
| Option | Max Load | Max Speed | Max Temp | Best For |
|---|---|---|---|---|
| JDB graphite | Very high | Low–medium | ~300–400°C | Heavy, hot, dirty |
| PTFE composite | Medium | High | ~200°C cont. | Fast, light, precise |
| Oil bronze (grooved) | High | Medium | Limited by oil | Lubricated, long-life |
Need help choosing? Our self-lubricating bearings guide compares all solid-lubrication families side by side.
Material Selection
Bronze Alloy Composition
Casting
Centrifugal casting, continuous casting
Machining
Precision Machining
Quality Inspection
Material Testing, Surface Inspection
Get a Quote for JDB Graphite Bearings
Send your drawing, duty cycle, and temperature range — we’ll recommend the grade and plug layout.
