Custom Bearing Bronze: Parts Machined to Your Drawing
A custom bearing bronze part is a sleeve, flange, thrust face or wear plate machined to a drawing instead of picked from a catalogue. The reasons buyers come to us are usually ordinary: an obsolete part with no spare, a housing that was modified in the field, a load the standard size will not carry, or a lead restriction that rules out the alloy the machine was originally built with. This page sets out the forms we machine, the alloys behind them, the dimensional ranges that are practical, and the cases where bronze is not the right answer.
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With decades of experience in the bearing industry, we excel in designing and manufacturing high-performance oilless bearings that offer reliable and durable solutions.
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We collaborate with our clients to create bearings that maximize efficiency and durability, considering size, material selection, and performance characteristics.
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High-Performance Bearing Bronze – Part forms that get made to drawing
Most enquiries fall into one of six shapes. The shape usually decides the manufacturing route before the alloy does:
- Plain cylindrical bushings (sleeves) — pressed into a housing bore. The most common request and the one where wall thickness matters most, because a thin wall needs a housing bore that is round and true.
- Flanged bushings — a sleeve with a flange that takes axial load and locates the part. Common in agricultural and construction equipment where the thrust is intermittent and dirty.
- Thrust washers and half washers — flat annular faces that carry axial load between a rotating and a stationary face. Frequently specified when an existing roller thrust bearing has failed from lubrication starvation. Examples are shown under bronze wear plate and flat thrust parts.
- Wear plates, strips and gibs — flat or L-section pieces bolted or welded into slideways, machine beds and gib assemblies.
- Split and half bushings — used where the shaft cannot be withdrawn. Machined as two halves with a joint face, which means the bore must be finish-machined after the halves are clamped.
- Bushings with special features — counter-sunk bolt holes, keyways, oil holes, spiral or figure-eight grooves, diamond-pocket lubricant patterns, and spherical or self-aligning outside diameters.
If the drawing carries a part number from the original equipment manufacturer, send that too. Cross-referencing against the machine model is often faster than reverse-engineering from dimensions alone.
Explore durable and wear-resistant bearing bronze materials ideal for industrial and high-load applications. Engineered for longevity and reliability.
Bearing Bronze Alloys – SAE 660, 932 & More
Custom Machined Bearing Bronze Parts
custom b earring bronze Alloy selection
The table below lists the alloys we machine most often. Figures are typical room-temperature values for cast or continuous cast stock; the mill certificate that ships with the order governs. Where a drawing names an alloy by a trade or catalogue number rather than a standard designation, we ask for the standard revision before quoting.
| Designation | Family | Nominal composition, typical ranges | Tensile strength, typical | Hardness, typical | Typical machined parts |
|---|---|---|---|---|---|
| C93200 (SAE 660) | Leaded tin bronze | Cu 81–85%, Sn 6.3–7.5%, Pb 6–8%, Zn 1–4% | 240–310 MPa (35–45 ksi) | 60–75 HB | General purpose sleeve and flanged bushings, pump and valve guides |
| C90500 (SAE 62) | Tin bronze, low lead | Cu 86–89%, Sn 9–11%, Zn 1–3%, Pb up to 0.3% | 275–345 MPa (40–50 ksi) | 75–95 HB | Higher load gears and bushings, continuous caster and steel plant parts — see C90500 tin bronze bushings |
| C95400 (CuAl11Fe4) | Aluminum bronze | Cu balance, Al 10–11.5%, Fe 3–5% | 585–690 MPa (85–100 ksi) | 170–200 HB | Marine, chemical and high-load slow-speed service |
| C86300 | Manganese bronze (a high-tensile brass) | Cu 60–66%, Zn 22–28%, Al 5–7.5%, Fe 2–4%, Mn 2.5–5% | 760–860 MPa (110–125 ksi) | 225–280 HB | Very high static load, low speed, impact and dirty conditions — see C86300 manganese bronze bushings |
| CuSn8 (CW453K, close to C52100) | Phosphor bronze, lead-free | Cu balance, Sn 7.5–8.5%, P 0.01–0.4% | 450–600 MPa (65–87 ksi) | 90–150 HB | Wrapped bushings, food contact and RoHS-restricted equipment — see C52100 phosphor bronze bushings |
| C51000 (CuSn6, CW452K) | Phosphor bronze | Cu balance, Sn 4.2–5.8%, P 0.03–0.35% | 400–550 MPa (58–80 ksi) | 80–140 HB | General bushings, electrical and spring-tempered parts |
Two naming traps come up repeatedly. C86300 is called manganese bronze but is metallurgically a high-tensile brass (copper-zinc-aluminium), not a tin bronze. And CuSn8 appears in catalogues both as a wrought phosphor bronze and as the base for wrapped bushings, so the product form needs stating alongside the designation.
Where the load case is moderate and the environment is clean, C93200 and C51000 cover most of it. The step up to C95400 or C86300 is justified by load, temperature, corrosion or impact, not by habit — both cost more per kilogram and both are harder on the shaft. A wider comparison sits in the bushing material overview.
Lubrication built into the part
A machined bronze part can be plain, grooved, or built with a solid lubricant. Choosing between them is mostly about whether anyone will be able to reach the bearing with a grease gun later.
| Option | How it works | Friction coefficient, typical | Usable temperature window, typical | Notes |
|---|---|---|---|---|
| Machined grease grooves | Groove stores grease and feeds the contact | 0.10–0.20 while greased | Limited by the grease, commonly to 120–150 °C (250–300 °F) | Needs a relubrication interval; groove edges must be deburred |
| Graphite plugs in cast bronze | Solid lubricant shears into a transfer film on the shaft | 0.08–0.16 | −40 °C to +300 °C (−40 °F to 570 °F) | Suits slow, heavy, oscillating motion; needs movement to form the film |
| MoS₂ impregnated pockets | Same transfer mechanism, different solid lubricant | 0.06–0.12 | To roughly 350 °C (660 °F) in air | Oxidises above that and stops reforming the film |
| PTFE or POM composite liner on a metal backing | Polymer layer shears at low stress | 0.04–0.10 | −40 °C to +250 °C (−40 °F to 480 °F) | Lower load ceiling than bronze; good where space is tight |
| Oil-impregnated sintered bronze | Oil bleeds out of interconnected pores | 0.05–0.12 | −40 °C to +150 °C (−40 °F to 300 °F) | Sensitive to dirt ingress; pores can hold abrasive |
For graphite-plugged parts the plug layout is the design variable, not just the alloy. Coverage, plug diameter and pocket depth are sized from the contact area and the expected travel per cycle; the geometry is explained in calculating plug size for graphite-plugged bronze bearings, and typical plugged parts are listed with graphite bushings and bearings.
Sizes, tolerances and machining route
These are the ranges that come up in normal production. Anything outside them is possible but usually needs a different blank route and a longer lead time, so it is worth flagging early.
| Item | Typical value or practice |
|---|---|
| Bore diameter | 5–500 mm (0.2–20 in); larger diameters from centrifugal cast blanks on request |
| Outside diameter | 10–600 mm (0.4–24 in) |
| Plate and strip size | Up to about 1000 mm (39 in) long, thickness 6–60 mm (0.24–2.4 in) |
| Bore tolerance | ISO H7 to drawing, or to the fit the print calls out |
| Concentricity, bore to OD | 0.05–0.15 mm (0.002–0.006 in) depending on diameter and length |
| Bore surface finish | Ra 0.8–1.6 µm (32–63 µin) as machined; finer on request |
| Mating shaft | 300 HB or harder for aluminium and manganese bronze; Ra 0.4–0.8 µm (16–32 µin) recommended |
| Running clearance | Commonly 0.1–0.2% of shaft diameter, plus allowance for thermal growth |
Near-net-shape casting followed by finish machining removes appreciably less material than machining from solid bar, which shortens cycle time on larger diameters and reduces cost. Small quantities machined from continuous cast bar are usually faster because no tooling is needed. Most of this work runs on CNC turning centres, with prismatic features, bolt patterns and angled faces handled on multi-axis machining; the machining-only route is described under machined bronze bushings. Measurement practice for finished bores is covered in reading and measuring bearing tolerance.
Limits: when a custom bronze part is not the right call
- Rolling speeds with limited lubrication. A plain bronze bushing depends on a film. Where surface speed is high and there is no relubrication, a rolling bearing or a composite liner will usually outlast it.
- Soft or rough shafts. Aluminium bronze and manganese bronze are hard and do not embed dirt. On an unhardened shaft they tend to score the journal rather than polish it. Either specify a softer leaded tin bronze or harden the shaft.
- Graphite where there is no movement. A graphite-plugged part needs relative motion to build the transfer film. A support that only sees thermal creep once or twice a year will not develop one, and a plain bronze or PTFE-faced plate is the better choice.
- Strongly reducing acids or sulfidic media. Copper alloys are not suited to these; a lined steel or polymer component is normally specified instead.
- Very tight concentricity at long length-to-diameter ratios. Machining can hold the tolerance, but the housing bore and shaft deflection usually govern, so specify the housing condition as well.
- Cost-sensitive, light-duty, high-volume parts. If the load is low and the part is replaced rather than repaired, a powder metallurgy or polymer bushing will usually be cheaper per piece.
Lead content and compliance
Lead improves machinability and gives a leaded tin bronze its tolerance of marginal lubrication, but it restricts where the part can be used. Where the equipment falls under RoHS, drinking water contact rules, or a customer’s own restricted substance list, we quote lead-free or low-lead alloys: CuSn8, C90500, or aluminium bronze with a lead-controlled heat. Note that these alloys machine slightly differently and need a sharper edge and more consistent feeds, which shows up as a modest cost difference rather than a capability limit.
What to send for a quotation. Drawing or sketch with ID, OD, length and any flange; operating load and speed or oscillation angle; temperature range; mating shaft material, hardness and finish; surrounding medium; quantity per order and per year; any material standard or lead restriction. A photograph of the failed part and the housing often answers questions a drawing cannot.
Explore durable and wear-resistant bearing bronze materials ideal for industrial and high-load applications. Engineered for longevity and reliability.
Bearing Bronze Alloys – SAE 660, 932 & More
Custom Machined Bearing Bronze Parts
Customization Options at BronzeOilless.com
Tailor bearings to exact requirements with:
- Sizes: From 5mm shafts to 500mm industrial bushings.
- Types:
- Self-Lubricating Bushings (CuSn8 with graphite plugs).
- Split Bronze Bushings (Easy installation in confined spaces).
- Flanged Bushings (Axial load support in agricultural machinery).
- Thrust Washers (High-load rotary applications).
Crafting the high quality bronze and brass products you can trust, Serving you better!
Frequently asked questions
What is the smallest quantity you will make?
One piece is workable when a part is truly obsolete, though the setup cost per piece is high. The unit cost falls noticeably at around 20 to 50 pieces, and again once a dedicated casting pattern or fixture is justified. For spare-part programmes we usually quote a one-off development piece plus a production price.
Can you work from a sample part instead of a drawing?
Yes. We measure the sample, produce a drawing for your approval, and machine against the approved version. Send the sample uncut if possible — a part that has been sectioned loses the bore and wall data we need most.
Which alloy should I pick if the drawing only says “bronze”?
Give us the load, speed, temperature and medium and we will propose two options with numbers. Where the original part was a leaded tin bronze and nothing unusual is happening, C93200 is the common starting point. Where the shaft is hardened and the load is high, C95400 or C86300 is worth pricing alongside it.
How long does a custom order take?
For parts machined from stock bar, expect roughly two to four weeks from drawing approval including inspection. Centrifugal or continuous cast blanks add one to three weeks depending on size and alloy availability. Air freight and sea freight then determine the door-to-door figure.
Do you supply material certificates?
Yes. Each order ships with a mill certificate giving the heat composition and, where specified, mechanical test results. Dimensional inspection reports are available on request, and the tolerances we hold are described in oilless bearing specification.
