Cast Bronze Inch Sleeves in SAE 660 (C93200) – Standard and Custom Sizes for Industrial Bearing Applications
Cast bronze inch sleeves are cylindrical bearing sleeves supplied in fractional-inch inside diameters, used where the surrounding shaft and housing are dimensioned to imperial units. The default grade is SAE 660 (UNS C93200, the “high-leaded tin bronze”) cast to ASTM B505/B505M-23; for higher-load or corrosion-sensitive duty the sleeve is upgraded to C95400 aluminum bronze. Both materials are finished by boring, honing or grinding to the tolerance class you specify.
On this page: the standard ID and length combinations we keep in production, the SAE 660 and C95400 specifications, the cast methods we use, the working limits for load and PV, the lead-content question that matters for RoHS-restricted applications, and the data we need to quote a custom sleeve.
What is a cast bronze inch sleeve?
A cast bronze sleeve is a plain cylindrical bearing with no rolling elements. The “inch” in the name refers to the inside diameter dimensioning system: stock sizes run in fractions of an inch from 1/8″ to 1-15/16″, and the standard sleeve lengths for each ID are also fixed in whole inches or simple fractions. The sleeve is pressed into a housing bore and a shaft turns inside it, with oil or grease as the lubricant. Cast bronze is the most common sleeve material because it absorbs vibration, embeds minor abrasive particles without scoring the shaft, and survives momentary loss of lubrication without welding to the shaft.
Cast sleeves differ from rolled (wrought) bronze bushings in two practical ways. First, the cast structure has a small amount of porosity that helps maintain an oil film during start-up, which is why cast is preferred over rolled for slow-speed, high-load applications. Second, the cast method lets us pour near-net shapes (flanges, thrust collars, oil grooves) that a rolled bushing would need to be machined from solid stock. If your drawing shows anything beyond a plain cylinder, a cast sleeve is the lower-cost option.
Standard ID and length combinations (inch sizes)
The table below lists the standard inside diameters and the sleeve lengths available for each. All sizes are continuous-cast C93200 (SAE 660) unless otherwise specified. Sizes outside this table are quoted as custom runs; the lead time depends on whether the size is built from a tube blank (fast) or requires a dedicated centrifugal cast (longer).
| Inner diameter (ID) | Standard sleeve lengths | ||
|---|---|---|---|
| 1/8″ (0.125″) | 1″ | 2″ | 3″ |
| 3/16″ (0.188″) | 1-1/8″ (1.125″) | 2-1/8″ (2.125″) | 3-1/4″ (3.250″) |
| 1/4″ (0.250″) | 1-3/16″ (1.188″) | 2-3/16″ (2.188″) | 3-7/16″ (3.438″) |
| 5/16″ (0.313″) | 1-1/4″ (1.250″) | 2-1/4″ (2.250″) | 3-1/2″ (3.500″) |
| 3/8″ (0.375″) | 1-5/16″ (1.313″) | 2-3/8″ (2.375″) | 3-3/4″ (3.750″) |
| 7/16″ (0.438″) | 1-3/8″ (1.375″) | 2-7/16″ (2.438″) | — |
| 1/2″ (0.500″) | 1-7/16″ (1.438″) | 2-1/2″ (2.500″) | 4″ |
| 9/16″ (0.563″) | 1-1/2″ (1.500″) | 2-5/8″ (2.625″) | 4-1/4″ (4.250″) |
| 5/8″ (0.625″) | 1-9/16″ (1.563″) | 2-11/16″ (2.688″) | 4-1/2″ (4.500″) |
| 11/16″ (0.688″) | 1-5/8″ (1.625″) | 2-3/4″ (2.750″) | — |
| 3/4″ (0.750″) | 1-11/16″ (1.688″) | 2-7/8″ (2.875″) | 5″ |
| 13/16″ (0.813″) | 1-3/4″ (1.750″) | 2-15/16″ (2.938″) | — |
| 7/8″ (0.875″) | 1-13/16″ (1.813″) | — | — |
| 15/16″ (0.938″) | 1-7/8″ (1.875″) | — | — |
| 1-15/16″ (1.938″) | — | — | — |
If your required combination is not listed, send the dimensions through our custom bronze bushing service intake and we will confirm whether the size fits within the standard tube-blank envelope or needs a dedicated cast. Lead time for a standard size is typically 5 to 10 working days; a custom cast adds 20 to 30 working days for pattern and first-article inspection.
Material options: SAE 660 (C93200) and the C95400 upgrade
Two materials cover essentially every cast bronze inch-sleeve application. Both are covered by ASTM B505/B505M-23.
| Property | C93200 / SAE 660 (high-leaded tin bronze) | C95400 (aluminum bronze) |
|---|---|---|
| UNS / common name | C93200, SAE 660, “high-leaded tin bronze” | C95400, “aluminum bronze” |
| Tensile strength (continuous cast) | 44 000 psi (300 MPa) | 85 000 psi (585 MPa) |
| Yield strength at 0.5 % EUL | 22 000 psi (150 MPa) | 43 000 psi (295 MPa) |
| Brinell hardness (500 kg) | 60 HB | 170 HB |
| Elongation in 2 in | 20 % | 12 % |
| Machinability rating (free-cutting brass = 100) | 70 | 50 |
| Lead content | 6 – 8 % (intentional, for machinability) | < 0.05 % (essentially none) |
| Corrosion resistance (fresh water) | Good | Very good |
| Corrosion resistance (salt water) | Limited | Good |
| Typical duty | Pivot pins, linkage, slow-speed general bearings | Heavy-load bearings, marine, mining equipment |
Pick SAE 660 unless you have a specific reason to spend more. The three reasons to upgrade to C95400 are: (1) the calculated bearing pressure is above about 2 000 psi (14 MPa) sustained load, (2) the service environment is wet or mildly corrosive, or (3) the part must meet a no-lead specification (drinking-water contact, RoHS-restricted export markets). For deep sub-sea service or for high-PV pump impeller duty, consider C95500 nickel aluminum bronze instead — the nickel addition improves cavitation-erosion resistance by another order of magnitude over C95400.
Mechanical and physical properties in US customary units
Values below are for continuous-cast C93200 (SAE 660) per ASTM B505/B505M-23. For centrifugal-cast or sand-cast sleeves, the values are within the same range but the tensile and yield strengths sit at the lower end of the band. Forged or sintered alternatives are not covered here.
| Property | US customary | Metric equivalent |
|---|---|---|
| Density | 0.322 lb/in³ | 8.9 g/cm³ |
| Solidus / liquidus | 1570 °F / 1790 °F | 854 °C / 977 °C |
| Coefficient of thermal expansion | 10 × 10-6 /°F | 18 × 10-6 /°C |
| Thermal conductivity | 34 Btu/(ft·h·°F) | 59 W/(m·K) |
| Electrical conductivity | 12 % IACS | 0.07 MS/m |
| Specific heat capacity | 0.09 Btu/(lb·°F) | 377 J/(kg·K) |
| Modulus of elasticity | 15 000 ksi | 103 GPa |
| Poisson ratio | 0.34 | |
| Magnetic permeability | 1.0 (essentially non-magnetic) | |
Two practical points. First, the thermal-expansion coefficient is higher than steel by about 15 %, so a long C93200 sleeve fitted into a steel housing must be allowed clearance for axial growth; if the application sees more than about 30 °F (17 °C) of temperature swing, allow 0.001 – 0.002 in/ft of expansion gap or use a slotted housing. Second, the 12 % IACS conductivity means the alloy is conductive enough to behave as the cathode in any steel-to-C93200 galvanic couple, so where the shaft is steel the sleeve should be electrically isolated or the assembly sealed against electrolyte ingress.
Cast methods we use: continuous, centrifugal, sand
Three casting routes are used industrially for inch-size sleeves. The route chosen changes the unit cost and the metallurgical soundness.
- Continuous cast to ASTM B505 / B505M-23 — withdrawn tube and bar stock with uniform grain along the length. This is the form used for plain cylindrical sleeves (no flange) in the standard size table above; it is the lowest unit cost at quantity and gives the most consistent mechanical properties along the length.
- Centrifugal cast to ASTM B271 — the spinning mould throws denser metal to the outside, so the inner bore has fewer inclusions. Used for thicker-walled sleeves, for ID sizes that are not in the standard tube envelope, and for the flanged variants. Centrifugal cast is the route we recommend for any sleeve where the bore will see a heavy radial load.
- Sand cast to ASTM B148 — the most flexible method, used for short runs of hub-shaped or flanged sleeves where a permanent mould would not be economical. The grain is coarser than continuous or centrifugal cast, and the bore typically needs a heavier cut to clean up the cast surface; allow at least 0.060″ extra material on the ID for finish machining.
Most stocked inch sleeves are continuous cast. When you need a non-standard ID, an asymmetric flange or a particular OD that does not match a tube blank, we move the order to centrifugal or sand as appropriate; the price adder and the lead-time extension are quoted with the order acknowledgement.
Standard tolerances and how to read the table
The default tolerance band on a stocked inch sleeve is the “standard precision” column below. Closer tolerances are available on request and are quoted separately.
| Feature | Up to 3″ nominal | Over 3″ nominal | Tolerance grade equivalent |
|---|---|---|---|
| Inside diameter (ID) | ± 0.001″ | ± 0.0015″ | approx. ISO H7 (medium) |
| Outside diameter (OD) | + 0.002 to + 0.003″ | + 0.003 to + 0.005″ | approx. ISO k6 (press) |
| Length | ± 0.005″ | medium commercial | |
The ID tolerance is held on the as-machined bore; if you specify a honed finish, we tighten to ± 0.0005″ on the ID for the same nominal size. The OD tolerance band assumes the sleeve will be pressed into a housing bore; if the sleeve is a slip-fit rather than a press-fit, swap to + 0.000 / – 0.001″ (slip fit) or 0 / – 0.001″ (clearance fit). Concentricity of OD to ID is held within 0.001″ TIR on standard tolerances, within 0.0005″ TIR on the honed option.
Working limits: load, PV, temperature
Sleeve selection is governed by three numbers. The maximum load gives you the projected bearing area; the maximum PV product gives you the heat dissipation budget; the maximum continuous temperature gives you the lubrication envelope. All three apply simultaneously.
| Parameter | SAE 660 (C93200) at moderate speed | C95400 at moderate speed | Notes |
|---|---|---|---|
| Maximum bearing pressure | 2 000 – 3 000 psi (14 – 21 MPa) | 4 500 – 6 000 psi (31 – 41 MPa) | Sustained; shock loads up to 1.5× allowed for short cycles |
| Maximum PV (continuous) | 50 000 psi · fpm (typical for boundary lubrication) | 75 000 psi · fpm | Reduce by 50 % at temperatures above 300 °F (150 °C) |
| Maximum sliding speed | 1 200 fpm (6 m/s) | 1 500 fpm (7.5 m/s) | Higher speeds need flooded oil or hard-face overlay |
| Maximum continuous temperature | 450 °F (230 °C) with grease | 500 °F (260 °C) with grease | Above 450 °F, switch to solid graphite or PTFE dry film |
| Minimum operating temperature | – 20 °F (- 29 °C) with mineral grease | same | Below this, switch to synthetic grease (PAO / ester) |
The PV product is calculated from the projected bearing area (length × ID) and the sliding speed at the bore surface (π × RPM × ID). If the calculated PV exceeds the values in the table by more than 20 %, the sleeve needs forced lubrication, a different alloy, or both. The 450 °F ceiling for C93200 is the material limit; grease typically gives up around 350 °F, so the practical lubrication ceiling for stock inch sleeves is about 350 °F continuous with periodic re-greasing.
Lead content, RoHS and REACH
C93200 contains 6 – 8 % lead by weight, added deliberately to give the alloy its characteristic free-machining behaviour and its ability to embed abrasive particles. This lead content is the single most important specification question for export compliance.
| Regulation | Status of C93200 | Practical impact |
|---|---|---|
| EU RoHS (2011/65/EU + amendments) | Lead is a restricted substance above 0.1 % w/w in homogeneous material; exemptions cover some bearing alloys under specific categories | General industrial use is typically allowed under RoHS category exemptions; finished articles that come into contact with skin or food are restricted |
| EU REACH (Annex XVII) | Lead and lead compounds listed; concentration limits apply to articles placed on the EU market | C93200 sleeves imported into the EU must be assessed for the specific end use; routine industrial bearings are usually exempt under “machinery” provisions but should be confirmed case-by-case |
| US Safe Drinking Water Act / AB1953 / VT Act 193 | C93200 is NOT compliant for wetted components in potable water systems | Use C95400, C95500 or C87800 for drinking-water valve trim; see our C95500 nickel aluminum bronze page |
| California Prop 65 | Lead warning label required for articles that may cause exposure | Most cast bronze bearing sleeves shipped to California carry the standard Prop 65 warning |
If your application is in a market that restricts lead, the simplest path is to upgrade the sleeve to C95400 (or to a true lead-free alloy such as C87800 silicon bronze for low-load duty). Both materials are stocked in the same inch ID envelope; the unit price is higher but the compliance review is shorter.
Typical applications by sector
| Sector | Typical sleeve location | Why inch sleeves are specified |
|---|---|---|
| Agricultural machinery | Tractor loader pivots, harvester hitch pins, steering linkages | Dusty field environment; cast structure embeds grit without shaft scoring; greasable groove patterns are easily added |
| Construction and mining | Excavator arm pins, hydraulic cylinder rod guides, rock-crusher pitman bearings | Higher load capacity than machined-from-bar brass; absorbs vibration and shock loading |
| Fluid power | Shaft support sleeves in gear pumps and vane pumps, valve spools | Tight ID tolerance class supports spool metering accuracy; corrosion resistance to common hydraulic fluids |
| Industrial conveyor | Idler rolls, tail-pulley shafts, belt-tensioner pivots | Long sleeve lengths (3 – 5 in) are common; standard inch envelope covers the typical sizes |
| Material handling | Forklift mast rollers, crane slewing bearings | Wear resistance combined with low-cost replacement at the maintenance interval |
| Steel mill (auxiliary) | Coiler mandrel support, side-trimmer guide rolls | Use C95400 upgrade for elevated ambient temperature or for water/scale contamination |
One pattern across all sectors: the inch-sleeve form factor is most often selected when the surrounding machine is itself dimensioned in imperial units (North American-built agricultural and construction equipment is the typical case). For metric-machine applications the equivalent choice is the metric sleeve service; for plain-flange variants see square flange copper sleeve bearing or brass sleeve bushing.
Frequently asked questions about cast bronze inch sleeves
What is the difference between SAE 660 and SAE 841?
SAE 660 is C93200 high-leaded tin bronze, the general-purpose sleeve alloy covered on this page. SAE 841 is C54400 phosphor bronze, which contains no lead but has a higher tin content and is used where lead-free compliance is mandatory. SAE 841 is harder and stronger than SAE 660 but also more expensive and more difficult to machine. For most inch-sleeve applications SAE 660 is the right starting point; SAE 841 is the upgrade path when lead content must be near zero but C95400 or C95500 are not required.
Can I press a cast sleeve into a steel housing without a keyway?
Yes for most inch-sleeve applications, as long as the OD tolerance is the standard +0.002 to +0.003″ band and the housing bore is held to a similar negative tolerance. The press load is reacted through the shoulder at each end of the housing, not into the sleeve wall. For sleeves above about 4″ OD, or where the housing is a thin-walled tube rather than a solid block, add a small axial key or a light interference-fit adhesive bond to stop the sleeve creeping in service.
What is the difference between a cast sleeve and a sintered bronze bushing?
Cast sleeves are solid bronze, machined from cast bar or tube stock. Sintered bronze bushings are made by pressing and heat-treating bronze powder into a porous shape, then oil-impregnating the part so the bushing carries its own lubricant. Sintered bushings are quieter at low speed and need no external lubrication, but they have lower load capacity and limited temperature range. For inch sizes above 1/2″ ID and above about 2 000 psi sustained load, cast sleeves are the preferred choice; sintered bushings are more common in fractional horsepower motors and small instruments.
How is a cast sleeve different from a “wrapped” bronze bushing?
A wrapped bushing is made from a thin sheet of rolled bronze formed into a cylinder; it is cheaper than a cast sleeve for small-diameter, low-load applications and is typically the form factor stocked under 1″ ID. A cast sleeve is solid and is the form factor you need above 1″ ID, above about 2 000 psi load, or whenever the application includes a flange, an oil groove or a non-standard ID.
What is the typical lead time for a standard inch size?
5 to 10 working days for a standard size in continuous-cast C93200, starting from order confirmation. Custom sizes, flanged sleeves, C95400 upgrades and honed-finish ID all add 5 to 15 working days. If you need faster than that, the stocked inch envelope above covers most cases; for emergency orders contact us with the size and we will confirm whether a stocked blank is available for immediate machining.
How to request a quote
Send the drawing (PDF or STEP) plus the following five data points and we will come back with a price and a lead time within two working days:
- Finished ID and OD, with the tolerance class you need (default +0.002 to +0.003″ OD / ± 0.001″ ID).
- Length, with flange / hub dimensions if present.
- Annual quantity (for unit-price breaks) and the prototype quantity if different.
- Operating environment: dry / oil-lubricated / grease / water, plus temperature range.
- Material preference (SAE 660 / C93200 default) and any compliance requirement (RoHS, REACH, no-lead, drinking-water contact).
If you only have a sample or an existing part to copy, send the sample and we will reverse-engineer the dimensions, then mark up the drawing for your approval before we cut metal.
