Plain Bearing Materials: Grades, Properties and Selection

01.

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.

02.

Bespoke plain bearings

viiplus collaborates with customers to find tailored solutions, offering plain bearings in various materials, sizes, tolerances, and designs.

03.

Timely Delivery

Committed to meeting tight deadlines without compromising on quality, we ensure reliable and efficient production timelines.

04.

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 Custom Bearings & Bushings

A plain bearing fails for one of four reasons: the material is too soft for the load, it scores the shaft, the friction heat cannot leave the contact, or the environment attacks it. This page sets out how bearing materials are measured against those four failure modes, and compares the copper-based grades used for bushings, thrust washers and wear plates with the routes used to make them.

Custom Bearings & Bushings Machining Finished Parts, Machining Parts C61900，C86300，C83600，C93700，C90700,C95810，C95200

Custom Machined Bronze Parts & Bearings

What a bearing material has to do

Selecting a bearing material is a compromise between properties that pull in opposite directions. Hardness resists wear but reduces the material’s ability to absorb debris. Strength carries load but usually lowers conformability. The six properties below are the ones that decide whether a grade survives in a given application.

with graphite inserts Material: C86300 Manganese Bronze with Graphite Plugs
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C93200 (SAE660) Bronze Ring Leaded Tin Bronze Leaded Tin Bronze
flange groove bearing C93200 (SAE660) or CuSn7Zn4Pb7-C (CC493K) GC Leaded Tin Bronze

Oilless Bushing Material, Machining Parts

Custom Bearings & Self-Lubricating Bronze Bushing to Client Specifications

Discover the complete material selection and application matrix for oilless bronze bushings. Compare CuZn25Al5, CuAl10Ni, and ASTM/EN equivalents for heavy-duty industrial friction solutions.

 What a bearing material has to do

Selecting a bearing material is a compromise between properties that pull in opposite directions. Hardness resists wear but reduces the material’s ability to absorb debris. Strength carries load but usually lowers conformability. The six properties below are the ones that decide whether a grade survives in a given application.

Table 1 — Bearing material properties and why each one matters
Property What it governs What happens when it is low Raises it Lowers it
Compressive / fatigue strength Maximum bearing pressure before the material yields or spalls Plastic deformation, fatigue cracking under oscillating load Al, Fe, Ni additions; cast section High lead content, high porosity
Wear resistance Material loss rate at the sliding surface Clearance growth, loss of geometry Harder tempers, intermetallic phases, solid lubricant Soft annealed conditions
Embeddability Ability to absorb hard particles into the surface Particles score the shaft; three-body abrasion Lead, porosity, soft matrix High hardness, homogeneous structure
Conformability Ability to deform locally to accommodate misalignment and shaft deflection Edge loading, local overheating, seizure Soft matrix, thin overlay High yield strength
Compatibility (anti-seizure) Resistance to welding to the shaft under boundary lubrication Scoring, seizure, shaft damage Lead, tin, graphite, PTFE Steel-on-steel or stainless-on-stainless pairs
Thermal conductivity Removal of friction heat from the contact Temperature rise, oil film collapse High copper content, solid section Porosity, high alloy content, polymer layers

The two properties most often traded against each other are load capacity and embeddability. A high-strength aluminium bronze carries the highest bearing pressures in the table, but absorbs debris poorly; a high-lead tin bronze does the reverse. Contaminated, poorly filtered oil shifts the choice towards the softer alloy.

How to read the numbers: p, v and PV

Bearing material datasheets quote three figures that are frequently misread. Their definitions matter more than the values.

  • Bearing pressure p (N/mm²). Load divided by the projected area — bore diameter × length, not the curved contact area. Quoted separately for static and dynamic load; the static figure is always higher.
  • Sliding velocity v (m/s). Surface speed at the bore. For rotating shafts, v = π × d × n / 60 000 with d in mm and n in rpm. For oscillating motion, use the mean velocity over the stroke, not the peak.
  • PV value (N/mm²·m/s). p × v. It is a proxy for the rate of friction heat generation at the contact, and it is the figure that normally governs the design. A material rated at PV 2.8 will not accept 2.8 N/mm² at 1 m/s and 0.28 N/mm² at 10 m/s interchangeably, because the heat path and the film thickness differ at the two extremes — treat PV as a screening boundary, then check p and v separately.

Two figures that change the answer

Published PV values are measured under defined conditions — a hardened steel shaft, a stated surface finish, full oil or grease lubrication, and a fixed ambient temperature. Two corrections apply before a catalogue value is used as a design limit:

  • Temperature. Bearing surface temperature reduces the usable PV. Above roughly 100 °C the base oil in a grease degrades and the margin narrows; check the lubricant limit, not just the metal limit.
  • Duty cycle. Intermittent duty with long cooling periods tolerates a higher peak PV than continuous running at the same value. Continuous operation should be designed to a lower PV than the published figure.

Material families and process routes

The manufacturing route determines the geometry you can obtain as much as the properties you get. A wrapped bushing and a solid cast bushing of nominally similar chemistry are not interchangeable.

Table 2 — Process routes and the part forms each one produces
Route Typical form Wall thickness Where it is chosen Constraint
Continuous / centrifugal cast Solid and flanged bushings, wear plates, large-diameter sleeves 3 mm and up Heavy load, shock, large sections Machining allowance required; higher material use
Sand cast Large one-off parts, complex shapes, trunnion and stern-tube bushings Heavy Low volume, very large diameters Wider property scatter; porosity risk
Wrought strip, rolled and wrapped Thin-wall wrapped bushings to DIN 1494 / ISO 3547 0.75–3 mm Oscillating pivots, compact housings, high volume Limited to strip form; needs a rigid housing bore
Powder metallurgy (sintered) Self-lubricating sleeve and flanged bearings, near net shape Thin Maintenance-free, moderate load, high volume Porous structure limits load; not normally machined after sintering
Machined from solid stock Prototypes, custom geometries, grooved plates Any Low volume, tight tolerances, complex groove patterns Highest material and machining cost per part
Steel-backed with sintered or cast lining Bimetal bushes, thrust washers, strip Thin lining on steel High fatigue load in compact envelopes Requires press-fit housing; lining cannot be re-machined deeply

Grade comparison table

The grades below cover the majority of copper-based plain bearing applications. Values are typical or standard minimum values for guidance; confirm against the mill certificate for the specific casting or temper supplied.

Table 3 — Plain bearing material grades. EN designations marked near are the closest match by composition and application; verify the cross-reference before substituting across standards.
Grade EN / DIN (near) Common name Family HBW typ. Tensile MPa typ. Density g/cm³ Material page
C93200 CuSn7Zn4Pb7 (near) SAE 660 bearing bronze Leaded tin bronze 65 240 8.93 C93200
C93700 CuSn10Pb10 (near) SAE 64 High-lead tin bronze 60 240 8.86 C93700
C93800 CuSn7Pb15 (near) SAE 67 High-lead tin bronze 55 179 9.25 C93800
C95400 CuAl10Fe3 (near) Aluminium bronze Cu-Al-Fe 170 586 7.45 C95400
C95500 CuAl10Ni5Fe4 (near) Nickel aluminium bronze Cu-Al-Ni-Fe 195 690 7.53 C95500
C95800 CuAl10Ni5Fe4 (near) Nickel aluminium bronze Cu-Al-Ni-Fe 159 620 7.64 C95800
C86300 CuZn25Al5Mn4Fe3 (near) Manganese bronze High-tensile cast brass 225 795 7.83 C86300
CuSn8 / C52100 CW453K Phosphor bronze strip Wrought tin bronze 100–160 HV 370–540 8.80 CuSn8
CuSn12 CC483K Tin bronze Cast tin bronze 90–100 260–300 8.60 CuSn12
SAE 841 CuSn10 sintered (DIN 1850) Oil-impregnated sintered bronze Powder metallurgy 30–70 HRH 97 6.4–6.8 SAE 841
CuAl10Ni5Fe4 CW307G (wrought) Nickel aluminium bronze Wrought Cu-Al-Ni-Fe 170–200 650–750 7.60 CuAl10Ni5Fe4
CuZn25Al6Fe3Mn3 CW713R (near) High-tensile brass Graphite-plugged base 210 750 8.00 Graphite-plugged

Composition limits, cross-standard mapping and temper designations for each grade are given on Bronze Alloys for Bearings. This page does not repeat them.

Cast bearing bronzes

Cast tin bronzes remain the default choice for solid bushings, because their balance of strength, embeddability and machinability suits a wide load band. Within the family the lead content is the main variable.

Leaded tin bronzes (C93200, C93700, C93800)

Lead is present as discrete soft particles distributed through the copper-tin matrix. It does not alloy with copper. Its bearing function is twofold: it provides a low-shear film that resists seizure when the oil film breaks down, and it gives the material its embeddability — hard contaminant particles press into the soft lead phase instead of scoring the shaft.

  • C93200 (SAE 660) — Cu 83.0–86.0, Sn 6.3–7.5, Pb 6.0–8.0, Zn 2.0–4.0 %. The general-purpose bearing bronze. Machinability rating 70.
  • C93700 (SAE 64) — Cu 78.0–82.0, Pb 8.0–11.0, Sn 9.0–11.0 %. Higher lead raises the anti-seizure margin; used where lubrication is intermittent or where the shaft is not hardened.
  • C93800 (SAE 67) — Cu 75.0–79.0, Pb 13.0–16.0, Sn 6.3–7.5 %. Highest lead content in the group, and the lowest strength. Chosen for contaminated environments and soft shafts. Note the density of 9.25 g/cm³ — weight estimates based on a generic bronze figure will be low.

The trade-off is direct: as lead rises, embeddability and compatibility improve while tensile strength, fatigue strength and elevated-temperature capability fall. Do not specify a high-lead grade for a shock-loaded or high-PV application on the strength of its sliding properties alone.

Aluminium bronzes (C95400, C95500, C95800)

Aluminium bronzes carry the highest bearing pressures in this group and hold their strength at elevated temperature. Their corrosion behaviour in seawater and in many process fluids is why they are specified for marine and offshore and pump and valve duty. Two qualifications apply:

  • Sliding behaviour under boundary lubrication is less forgiving than that of leaded tin bronze. They are normally paired with a hardened shaft and a defined lubrication regime rather than used for dry running.
  • Machinability rating is lower — C95800 is rated at 50 against 70 for C93200 — which affects cost per finished part as well as cycle time.

C86300 manganese bronze

C86300 is named as a bronze but is metallurgically a high-tensile cast brass: the CDA places it in the cast brass group, with zinc at 22–28 % as the principal alloying element rather than tin. It has the highest strength of the grades in Table 3, at a typical 795 MPa tensile and 225 HBW, and it is a common base material for graphite-plugged bearings in mining and construction equipment. Its machinability rating is 8 on the CDA scale, the lowest of any grade on this page — the figure that governs how the part should be quoted and routed.

A recurring specification error

C86300 is frequently ordered as a bronze and rejected on receipt when the certificate shows a zinc-based chemistry. Name the UNS number and the governing standard (ASTM B505/B505M for continuous cast) on the drawing, and state “high-tensile cast brass” in the material description. The same caution applies to CuZn25Al6Fe3Mn3 bases used for graphite-plugged bearings.

Wrought tin bronze and wrapped bushings

CuSn8 (EN CW453K, UNS C52100) is supplied as strip and rolled into thin-wall wrapped bushings to DIN 1494 / ISO 3547. The alloy is work-hardened, so the specified temper determines the properties as much as the chemistry does.

Table 4 — CuSn8 tempers per EN 1652. State the temper on the drawing; chemistry alone does not define the part.
Temper Tensile MPa Yield MPa (approx.) Hardness HV Typical use
R370 370–450 ≈ 200 100–135 Formed parts needing ductility; deep-drawn forms
R450 450–540 ≈ 330 135–165 General-purpose wrapped bushings
R540 ≥ 540 ≈ 420 ≥ 165 Higher load or reduced wall thickness

Rated limits for CuSn8 wrapped bushings, per DIN 1494 / ISO 3547 published figures, depend on the lubricant as much as the alloy:

Table 5 — CuSn8 wrapped bushing rated limits. Values are reference figures for the bushing form, not for solid machined CuSn8.
Parameter Grease lubricated Oil lubricated
Maximum static load 120 N/mm² up to 140 N/mm²
Maximum dynamic load 40 N/mm² 40–70 N/mm²
Maximum sliding speed 2.5 m/s up to 10 m/s
Maximum PV value 2.8 N/mm²·m/s up to 10–16 N/mm²·m/s
Friction coefficient (lubricated) 0.05–0.25 0.05–0.15
Operating temperature −40 to +150 °C similar band

The spread between the grease and oil columns is why lubrication has to be stated on the enquiry. A wrapped bushing rated at PV 2.8 under grease is a different part from the same bushing in an oil bath. The operating temperature band is set by the lubricant, not by the alloy: CuSn8 itself tolerates a wider range than −40 to +150 °C, but standard grease does not.

Ultimate Engineering Guide to Oilless Bronze Bushings & Solid Lubricant Custom Bearings VIIPLUS Bearing Bushing SupplierLooking for technical advice?

Copper Alloy with Graphite Embedded Slide Bearing Bushings manufacturing combine harvester spare parts solid bushing, bronze with lubricant plugs embedded Cast Bronze Bushings with Solid Lubricant Inserts

Get a Quote for Your Custom Bearings & Bushings

Send your drawing or sample and receive a manufacturability review, alloy recommendation, and lead time — typically within one business day.

Custom Bronze Bushings: Grades, Types & Applications

    type of Custom Bearings & Bushings, Flanged Bearings, Custom Oilless Bronze Bushings, Custom Sliding Bearing

    C51000 Phosphor Bronze

    Custom Machined Phosphor Bronze Bushing.
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    C54400 Phosphor Bronze

    VIIPLUS Specialized in Bronze Sleeve and Flange Bearings.
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    C63000 Nickel Aluminum

    viiplus provide bronze sleeve bearings customized to meet the specific demands of our customers’ applications.
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    C86300 (SAE 430B) Manganese Bronze

    Your go-to resource for online bronze bearings and slide bearing.
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    C93200 (SAE 660) High Lead Tin Bearing Bronze

    Metals: Shop Alloy Thrust Bearing.
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    C95400 Aluminum Bronze Bearing

    Aluminum Bronze Bearing Material Specifications.
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    C95500 Nickel Aluminum Bronze Bearing

    Precision Machining Aluminum Bronze Groove Bushing
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    C95510 Nickel Aluminum Bronze Bearing

    In-house, advanced manufacturing processes such as CNC turning, CNC milling, grinding, lapping, and EDM.
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    Custom Bronze Bearing

    Our skilled engineers are available to expertly guide our manufacturing processes.
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    Custom Bearings & Bushings Materials & Alloys We Machine

    From Drawing to Delivery

    A reliable drawing to delivery workflow is what separates a parts supplier from an engineering partner. Our process keeps you informed at every gate:

    1. RFQ & requirement capture — drawing, quantities, and operating conditions (load, speed, temperature, lubrication, environment).
    2. DFM & quotation — our engineers review manufacturability, propose alloy and process, and return a quote with lead time.
    3. Sampling — first articles produced; dimensions and material verified against the drawing.
    4. Validation — fit, function, and (where needed) performance checks with your team.
    5. Mass production — released after sample approval, with in-process inspection.
    6. Inspection & certification — final QC plus material report where specified.
    7. Packaging & shipping — export cartons, wooden pallets, or cases per your requirement.

    Sampling typically runs from a few days to several weeks; production windows are quoted per order after sample sign-off. The same documentation travels with the part, so reordering is painless.

    As an OEM bearing manufacturer, VIIPLUS supports three engagement models:

    Build-to-Print

    You supply the drawing; we manufacture to it exactly, holding your tolerances and material spec. Ideal for replacement programs and sourced components with locked designs.

    Engineering-to-Order (Co-design)

    When performance targets matter more than a fixed geometry, our engineers help optimize alloy, lubrication, and form factor for cost and life. This is where a made to order bushing outperforms the catalog part.

    Reverse Engineering

    No drawing? Send the sample. We measure, analyze, and reproduce — or improve — the original part. A common path for obsolete equipment and urgent replacements.

    For OEM programs we protect your intellectual property with NDAs and disciplined drawing control: your geometry stays yours, and we do not reuse or resell customer-specific designs. Reorders reference the original part number and revision, so supply stays consistent across the product lifecycle.

    Tolerance & Certifications

    Precision is only meaningful if it is documented. VIIPLUS operates under quality system, with inspection at every production stage.

    Dimensional Tolerances

    Standard precision machining is available for sleeves, flanges, thrust washers, and plates, with special dimensions and fits produced to your drawing. We control bore, OD, length, running clearance, and surface finish to keep mating tolerance stack-up low — especially on integral-shaft designs.

    Material Certificates

    Third-party inspection and alloy traceability can be arranged per project, supporting marine, energy, and regulated-industry requirements.

    Frequently Asked Questions

    What files do you need for a custom bearing order?

    Please share your 2D drawings (PDF/DWG) and 3D models (STEP/IGES), with key dimensions and tolerances, plus operating parameters: load, speed, temperature, lubrication method, and working environment. If you only have a physical sample, we can perform reverse engineering and measure it to produce a drawing.

    What is your minimum order quantity (MOQ) for non-standard bearings?

    Non-standard and made-to-order bearings are typically accepted in small batches, depending on the manufacturing process (CNC machining, casting, or sintering). Prototypes and low-volume runs are supported; final MOQ is confirmed after we review your drawing and process route.

    What is the lead time for custom bearings?

    Sampling usually takes from a few days to several weeks depending on complexity and material availability. Mass-production lead time is quoted separately per order, with typical production windows in the range of 1 to 4 weeks after sample approval.

    What certifications and material reports do you provide?

    We operate under quality system. Material certificates are available on request, along with third-party inspection reports where required. RoHS/REACH and specific alloy traceability can be supplied per project.

    Can you reverse engineer a bearing from a sample?

    Yes. If you do not have a drawing, we can measure and inspect your physical sample, reproduce its geometry and material, and deliver a matched or improved custom bearing. This is a common route for obsolete or replacement parts.

    bronze bearing cast parts2

    Material Selection

    Bronze Alloy Composition

    Centrifugal Casting1

    Casting

    Centrifugal casting, continuous casting

    Machine tool bearing

    Machining

    Precision Machining

    Vernier caliper measurements on the piston

    Quality Inspection

    Material Testing, Surface Inspection

    VIIPLUS Industries Served, Custom Bearings & Bushings Material

     Sintered bronze (SAE 841)

    SAE 841 is the reference designation for oil-impregnated sintered bronze. The porous structure, typically 19–25 % by volume, is vacuum-impregnated with oil; rotation heats the bushing, oil expands and migrates to the surface, and capillary action draws it back when the shaft stops. The cycle is self-sustaining for the life of the oil charge, which is why these bearings are specified where scheduled relubrication is not practical.

    Table 6 — SAE 841 typical specification. Equivalent designations: ASTM B438/B438M Grade 1 Type II, MPIF CT-1000-K26, ISO 5755 CTG 1001, DIN 1850, GB/T 5143, AMS 4805.
    Parameter Value Note
    Copper 87.5–90.5 % Matrix
    Tin 9.5–10.5 % Strength and wear resistance
    Iron ≤ 1.0 % Grain refinement
    Graphite ≤ 0.3–0.5 % Limit differs by standard edition
    Density 6.4–6.8 g/cm³ Solid tin bronze is ≈ 8.8 g/cm³
    Porosity ≥ 19 % vol Commonly 19–25 %
    Oil content 18–27 % vol Varies with impregnation practice
    K strength constant (radial crush) ≥ 26 500 psi (≈ 180 MPa) The figure in the MPIF designation CT-1000-K26
    Hardness 30–70 HRH Apparent hardness; Brinell crushes the porous structure
    Maximum dynamic load ≈ 14–15 N/mm² PV is the binding constraint
    Maximum sliding speed ≤ 6 m/s (≈ 1 200 sfpm) Higher than iron-based P/M grades
    PV limit ≈ 1.6–1.8 N/mm²·m/s Primary selection boundary
    Service temperature −10 to +105 °C Standard oil; synthetic oil extends to ≈ +150 °C

    Two characteristics shape how the material is used. First, the porous structure is load-limiting — the PV figure of roughly 1.6–1.8 N/mm²·m/s is well below that of solid cast or wrapped bronze, so sintered bronze occupies the moderate-load, high-volume, maintenance-free end of the range rather than the heavy-duty end. Second, it is produced to net shape and is not normally machined afterwards; cutting the bore would smear the surface and close the pores that carry the oil.

    For applications needing the maintenance-free behaviour of sintered bronze at higher load, the usual route is a graphite-plugged bronze bushing on a solid cast base.

    Graphite-plugged bronze

    Graphite-plugged bearings use a cast bronze or high-tensile brass body with solid lubricant plugs inserted in a pattern across the sliding surface. As the bearing runs, a transfer film of graphite forms on the shaft; the plugs are consumed slowly rather than the metal wearing. The base alloy carries the load and the plugs supply the lubrication, so the two are selected together.

    Table 7 — Base alloys for graphite-plugged bearings and the duty each one suits
    Base alloy HBW typ. Tensile MPa typ. Chosen for Avoid where
    CuZn25Al6Fe3Mn3
    high-tensile brass    		 ≥ 210 ≥ 750 Heavy load at low speed; general-purpose self-lubricating service Seawater immersion, ammonia-bearing environments
    CuSn8 / CuSn10
    tin bronze    		 90–120 300–450 Moderate load with better corrosion behaviour; food and packaging machinery Highest load classes
    CuAl10Ni5Fe4 / C95400
    aluminium bronze    		 170–200 600–750 Seawater, splash zones, hydraulic structures Soft shaft; unlubricated start-up under shock
    C86300
    manganese bronze    		 225 795 Highest load classes; mining and earthmoving pivots Applications calling for a tin-bronze certificate

    Plug layout is a design variable, not a fixed feature. Coverage is commonly 20–30 % of the sliding surface. Three constraints govern the pattern: plugs must not cross an oil groove or a split line; the layout must provide continuous coverage through the full arc of oscillation, which for an oscillating pivot is often less than the full circumference; and plug depth is limited by wall thickness, so thin-wall designs take fewer, smaller plugs. See Graphite-Plugged Bronze Bearings for layout patterns and groove interaction.

     Steel-backed and PTFE-lined bearings

    Where the load exceeds what a solid bronze section can carry in the available space, or where the envelope is too thin for a wrapped bushing, the load is carried by a steel backing and the sliding function is provided by a thin lining. Three constructions are in common use:

    • Bimetal — steel with a sintered bronze or lead-bronze lining. Combines the fatigue strength of the steel back with the sliding properties of a copper alloy. Used in gearboxes, hydraulic cylinder eyes and connecting rod small ends.
    • Steel-backed PTFE composite. A sintered bronze interlayer on steel, impregnated and overlaid with a PTFE and filler mixture. Runs dry with a low friction coefficient and is used where external lubrication is not available or where contamination must be excluded — see PTFE Composite Bearings.
    • Steel-backed with a polymer or overlay coating. Selected for specific combinations of load, temperature and chemical exposure.

    The governing limits here differ from solid bronze: PV figures are quoted for the lining, and the fatigue strength of the assembly is set by the steel back and by the quality of the bond, not by the copper alloy. Re-machining the bore is limited to a small finishing allowance; cutting through the lining defeats the design.

    Operating limits compared

    The figures below are reference ranges for comparing material families, not design allowable limits. They assume a hardened steel shaft, the stated lubrication regime, and ambient temperature.

    Table 8 — Comparative operating limits. Verify against the specific product datasheet before use in design.
    Material Max dynamic load N/mm² Max speed m/s PV limit N/mm²·m/s Lubrication assumed Max temp. °C
    Leaded tin bronze (C93200) ≈ 55 2.5–3 ≈ 1.5 Oil or grease ≈ 200
    High-lead tin bronze (C93800) ≈ 40 2–3 ≈ 1.2 Oil or grease, marginal ≈ 180
    Cast tin bronze (CuSn12) ≈ 60 3–5 ≈ 2.0 Oil or grease ≈ 250
    Wrapped CuSn8 40 2.5 2.8 Grease 150
    Wrapped CuSn8 40–70 up to 10 up to 10–16 Oil 150
    Aluminium bronze (C95400 / C95500) ≈ 70–90 3–5 ≈ 2.5–3.0 Oil or grease ≈ 300
    Manganese bronze (C86300) ≈ 90–100 1–2 ≈ 3.5 Grease; often graphite-plugged ≈ 250
    Graphite-plugged bronze 40–100 0.3–1.5 1.0–1.6 Self-lubricating ≈ 300
    Sintered bronze (SAE 841) 14–15 6 1.6–1.8 Oil-impregnated 105

    Read the load and speed columns together. Graphite-plugged bronze accepts a high bearing pressure at very low speed — it is designed for oscillating pivots and slow rotation — but its PV limit is low because plug consumption is proportional to sliding distance. Sintered bronze is the reverse: a low load limit, but a higher permissible speed.

    Speed is the constraint most often overlooked

    Enquiries frequently specify load and omit speed, or give motor rpm without the bore diameter. Without both, the PV value cannot be calculated and the material cannot be selected on anything other than habit. Give bore diameter, load, speed or oscillation angle and cycle rate, and duty cycle together.

    Shaft, housing and clearance

    The bearing material is only one half of the sliding pair. Surface finish and hardness of the counterface affect wear rate as strongly as the alloy choice does.

    Table 9 — Counterface and fit requirements commonly specified with copper-alloy plain bearings
    Parameter Typical requirement Why it matters
    Shaft hardness ≥ 45–55 HRC for wrapped bushings and aluminium bronze Soft shafts wear and score against hard bearing alloys
    Shaft surface finish Ra ≤ 0.8 µm, preferably Ra 0.2–0.4 µm Peaks cut the bearing and break the oil film; overly smooth surfaces retain no lubricant
    Housing bore H7 Controls the press fit and the installed bore
    Shaft tolerance f7 / f8 Sets the running clearance
    Installed bore (wrapped bushings) H9 The bore closes on installation; the finished size is that of the installed bushing
    Running clearance Typically 0.5–1.5 ‰ of bore diameter Bronze expands more than steel; insufficient clearance causes seizure as temperature rises

    Differential thermal expansion is the reason clearance is set as a percentage of bore rather than as a fixed value. The coefficient of thermal expansion for copper alloys is around 17–18 × 10⁻⁶ /K against roughly 11–12 × 10⁻⁶ /K for steel, so a bushing running hot closes onto a cooler shaft. Applications with a wide ambient temperature range, or with a bronze bushing in a steel housing, need the clearance checked at both temperature extremes.

    Selection by operating condition

    Work through the table below in order: load and speed first, then lubrication, then environment. Where two conditions point to different materials, the lubrication regime usually decides between them.

    Table 10 — Material selection by operating condition
    Condition Start with Reason Related page
    Heavy static load, slow oscillation, no relubrication Graphite-plugged high-tensile brass or C86300 Base alloy carries the pressure; plugs supply the film Graphite-plugged
    Moderate load, continuous rotation, oil bath C93200 or cast tin bronze Balanced strength, embeddability and machinability Bronze bushings
    Oscillating pivot, thin wall, grease CuSn8 wrapped bushing, ISO 3547 PV 2.8 under grease; compact section Bronze bushings
    High load, shock, misalignment, contaminated High-lead tin bronze (C93700, C93800) Embeddability and conformability absorb debris and deflection C93800
    Seawater, splash zone, immersion CuAl10Ni5Fe4 / C95500 / C95800 Corrosion behaviour in chloride environments Marine & offshore
    Maintenance-free, moderate load, high volume SAE 841 sintered bronze Oil-impregnated, net shape, quiet running SAE 841
    Dry running, thin envelope, no lubrication Steel-backed PTFE composite Low friction without external lubricant PTFE composite
    Food contact, washdown Lead-free tin bronze or specified composite; confirm the contact requirements Lead content and cleanability both govern Food & packaging
    Elevated temperature above 200 °C Aluminium bronze or graphite-plugged; verify the lubricant limit Strength retention; the oil or grease fails before the metal does C95400
    Submerged or water-lubricated Specified water-lubricated grades; confirm the water chemistry Film formation in water differs from oil; abrasive content matters PTFE composite

    Material page index and page template

    Each grade has its own material page covering the full specification, and each follows the same structure. Uniformity across the pages is deliberate: the same properties appear in the same order at the same position on every page, which is what lets a reader compare two grades without re-reading the whole page.

    The template every material page follows

    1. Summary — what the material is, its family, and the duty band it covers. Three or four sentences.
    2. Composition — element limits with the governing standard named.
    3. Mechanical and physical properties — hardness, tensile, yield, elongation, density, thermal conductivity, CTE, by temper or cast condition.
    4. Bearing performance — allowable load, speed and PV by lubrication regime, in a table.
    5. Cross-reference — UNS, EN, DIN, JIS, GB, BS designations, with near-equivalent matches flagged.
    6. Manufacturing notes — process routes, machinability rating, heat treatment, joining, groove and plug capability.
    7. Typical applications — by industry, with links to the corresponding industry pillar.
    8. Specification checklist — the data needed to quote, plus the failure modes that indicate the material is the wrong choice.

    Keep each child page below its parent in length. A child material page that outgrows the hub it belongs to is competing with it for the head term, which is the cannibalisation pattern this structure is built to avoid.

    Specification worksheet

    An enquiry that carries the following data can be answered with a material recommendation and a quotation. Missing items are the usual cause of a second round of questions.

    • Load — magnitude, direction (radial, axial, combined), static or dynamic, and whether shock loading occurs.
    • Motion — rotating or oscillating, speed in rpm or m/s, and for oscillating duty the angle and cycle rate.
    • Dimensions — bore, outside diameter, length, and any flange. For wrapped bushings, the housing bore and the wall thickness available.
    • Lubrication — oil, grease, dry, or water; relubrication interval; whether the bearing is sealed.
    • Temperature — steady-state and peak bearing surface temperature, and ambient range.
    • Environment — seawater, dust, chemicals, washdown, radiation; whether food contact applies.
    • Shaft — material, hardness, surface finish, and tolerance.
    • Volume and lead time — annual quantity, batch size, and whether prototypes are required first.
    • Documentation — material certificate type, inspection requirements, dimensional report.

    Frequently asked questions

    What is the PV limit and how is it used?
    PV is bearing pressure multiplied by sliding velocity, expressed in N/mm²·m/s. It represents the rate at which friction heat is generated at the contact, and it is normally the governing screening criterion for a bearing material. Calculate p from the projected area, calculate v from bore diameter and speed, multiply them, and compare with the material’s published PV for the lubrication regime in use. Then check p and v separately against their own limits, because PV alone does not describe the contact conditions.
    Is C86300 a bronze?
    By name it is manganese bronze, but the Copper Development Association classifies it in the cast brass group: zinc at 22–28 % is the principal alloying element rather than tin. In bearing practice it is grouped with bronzes because of how it is used, but a material certificate will show a Cu-Zn-Al-Mn-Fe chemistry. State the UNS number and ASTM B505/B505M on the drawing so the classification is not left to interpretation.
    Can a bronze bushing run against an unhardened shaft?
    It depends on the alloy and the hardness ratio. Softer, leaded tin bronzes run acceptably against unhardened shafts and are chosen for that reason where shaft cost or repair matters. Aluminium bronzes and wrapped CuSn8 bushings are normally specified with a shaft at 45–55 HRC or above, because the harder alloy will score a soft counterface. As a working rule the shaft should be at least three times harder than the bearing material.
    Why does the same grade show different property values on different datasheets?
    Three reasons, in order of frequency: the cast condition or temper differs (continuous cast, sand cast, centrifugal cast, and R370/R450/R540 tempers all give different figures); the source quotes typical values where another quotes standard minimum values; and some supplier tables repeat values that have been copied without checking against a standard. Use the governing standard and the cast condition on the drawing, and confirm against the mill certificate.
    When is graphite-plugged bronze the right choice over sintered bronze?
    When load is higher and speed lower. Graphite-plugged bearings work at pressures up to roughly 40–100 N/mm² but at sliding speeds generally below 1.5 m/s, because plug consumption rises with sliding distance. Sintered bronze is the opposite: a load limit around 14–15 N/mm² but speeds up to about 6 m/s. Both are maintenance-free, but they sit at different points on the load-speed plane.
    Does lead content affect regulatory compliance?
    Yes. Leaded bearing bronzes contain 6–16 % lead and are affected by restrictions that apply to lead in certain product categories and applications, including some food-contact and potable-water uses, and reporting obligations under substances legislation in the EU. Where the end use is regulated, specify a lead-free grade or obtain the exemption position in writing before release. The composition table on the relevant material page and the mill certificate are the documents to check.
    How much running clearance should be allowed?
    A common starting point is 0.5–1.5 ‰ of bore diameter, then check it against the operating temperature range. Copper alloys expand at roughly 17–18 × 10⁻⁶ /K against about 11–12 × 10⁻⁶ /K for steel, so the clearance closes as the bearing warms. Applications with a wide ambient range, or with a bronze bushing in a steel housing, need the clearance verified at both extremes.
    Can a sintered bronze bushing be machined to size?
    Normally no. Machining smears the surface and closes the pores at the bore, which is where the oil film is generated. Sintered bearings are produced to net shape with a sizing operation that sets the final dimensions, and secondary operations are limited to those that do not disturb the porous bore surface. Where a specific tolerance is required that sintering cannot hold, use a machined solid or wrapped bushing.
    CuAl10Fe2
    CuSn11P
    CuSn7Zn4Pb7
    CuZn33Pb
    CuAl10Fe
    CuAl10Ni3Fe2
    CuSn11Pb2
    CuSn10Pb10
    CuAl10Ni
    CuAl10Fe5Ni5
    CuSn12
    CuZn25Al5Mn4Fe3
    CuZn25Al5

    CuAl11Ni

    RG7
    CuAl11Fe6Ni6
    CuSn12Ni2
    CuZn34Mn3Al2Fe1
    CuZn34Al2
    CuSn5ZnPb
    CuSn10

    CuSn5Zn5Pb5

    CuZn32Al2Mn2F31
    CuZn35Al1
    CuAl10NiFe4
    CuSn7ZnPb
    C95800
    C52400
    C91700
    C83600
    C95400*
    C90500
    C86300
    C93200*
    C90500
    C86200

    Machined Bronze Components

    Custom Bearings & Bushings from Client Drawings

    Special Custom Bearings Bronze Alloy

    Custom Bearings & Bushings International Service

    Self-Lubricated Custom Bearings & Bushings Functionality

    Custom Bearings & Bushings size Production