Cast solid bronze
One material through the wall, machined from continuous-cast or centrifugally cast stock; grooves and holes as designed; thickness free.
Sleeve bushings →Six constructions · five alloy families · three shapes
Types of bronze bushings – construction, alloy and shape
Bronze bushings are sorted three ways. The construction – how the bronze is made into a bearing – decides lubrication and speed. The alloy decides load and medium. The shape decides how it fits. This site makes one construction, the machined solid cast bronze bush; the table tells you honestly when one of the other five is the better part and where to get it.
A bronze bushing is a plain bearing whose sliding surface is a copper alloy. Six constructions are in common use: solid bushes machined from cast bronze; sintered bronze impregnated with oil; thin-wall bushes wrapped from bronze strip; bimetal bushes with sintered bronze on a steel back; cast bronze with graphite plugs; and metal-polymer bushes with a PTFE-based liner on steel. They overlap in shape and alloy but not in duty.
- Cast solid: highest load and shock, any size, any alloy, re-machinable – needs grease or oil
- Sintered oil-impregnated: self-lubricating for light loads and small sizes, cannot be re-machined
- Wrapped: thin-wall, high volume, oscillating, greased; sizes to about Ø100
- Bimetal: thin-wall, steel-backed, press-fit accuracy from the housing, greased
- Graphite-plugged: cast bronze that runs without relubrication, to 400 °C
- Metal-polymer: maintenance-free, low friction, higher speed, lower load and temperature
By construction – the decision table
Figures in the cast solid row are the general limits we confirm for machined cast bronze bushes; the other rows are qualitative – exact figures depend on the maker's material and are on the sister sites.
| Construction | Lubrication | Load | Speed | Temperature | Sizes | Cost | Choose it when |
|---|---|---|---|---|---|---|---|
| Cast solid bronze (this site) | grease or oil, grooves | dynamic to 25 N/mm², static to 45 N/mm² – highest of the six | to 0.5 m/s (higher with oil) | −40 … +250 °C | Ø3 – 1000 mm, any wall, any alloy | medium; scales with weight | heavy load, shock, edge loading, large diameter, drawings, re-machining, alloy choice, small batches |
| Sintered oil-impregnated bronze (Oilite type) | self-lubricating (oil in pores) | low – about a quarter of cast | low to moderate | to about 100 °C | small standard sizes | low in volume | light loads, small motors and appliances, no relubrication, high volume |
| Wrapped bronze (CuSn8 strip) | grease, pockets or holes | medium | low, oscillating | to about 150 °C | thin wall, to about Ø100 | low in volume | thin-wall series parts, oscillating, weight and space limits |
| Bimetal (steel back, sintered bronze lining) | grease | medium – high | low – moderate | to about 150 °C | thin wall, series | low – medium in volume | accurate thin-wall press fits in volume, automotive and hydraulic components |
| Graphite-plugged cast bronze | solid lubricant plugs; no relubrication | high (cast bronze base) | low | to about 400 °C | like cast bronze | higher | positions that cannot be greased, high temperature, ovens, steel plants, water |
| Metal-polymer (PTFE liner on steel) | maintenance-free, dry | medium | higher | to about 250 °C | thin wall, series | low – medium | high speed and low load, dry running, low friction, hydraulics |
Not sure which construction? Send load, speed, lubrication and temperature – we say which type, even when it is not ours.
The six constructions in section
What is bronze, what is steel, where the lubricant is.
Sintered oil-impregnated
Pressed and sintered bronze powder, 15 – 25 % porosity filled with oil; oil is drawn out by heat and returns when cool; no re-machining (it closes the pores).
Wrapped bronze
CuSn8 strip rolled into a bush with a butt joint; thin wall (1 – 2.5 mm), lubrication pockets or holes; takes its final shape in the housing.
Wrapped bronze bushings site →Bimetal
Steel strip with 0.3 – 0.8 mm of sintered bronze rolled into a bush; steel takes the press fit, bronze does the sliding.
Bimetal bushings site →Graphite-plugged bronze
Cast bronze bush with drilled holes filled with graphite-based solid lubricant covering 25 – 30 % of the surface; lubricant film forms as the bush runs.
Graphite-plugged bronze bushings site →Metal-polymer
Steel back, porous bronze layer, PTFE-based running layer 0.01 – 0.03 mm; low friction dry, limited load and wear life.
Metal-polymer bearings site →By alloy
Within the cast solid construction, five alloy families cover the duties: leaded tin bronze (C93200 / SAE 660, SAE 64, SAE 67) for general and dirty positions with soft shafts; tin and phosphor bronze (CuSn12, CuSn10P) for higher pressure and wear with hardened shafts; gunmetal (LG2 / C83600) for water, pumps and valves; aluminium bronze (C95400, C95500) for heavy load, heat and seawater; high-strength brass (C86300) for the heaviest shock loads. "932 or 954?" – 932 (C93200) for general duty to 25 N/mm² on unhardened shafts, 954 (C95400) for heavier load, heat or corrosion on a hardened shaft.
By shape
Sleeve (cylindrical) bushings take radial load in a through-bore; flanged bushings add axial location and a thrust face; thrust washers take axial load alone; wear plates and half bearings are the flat and split relatives. All are machined from the same stock in the same alloys, with grooves and holes as needed.
Names you will meet
Different trades use different words for the same parts:
- Bushing / bush / bearing bush
- the same part; "bushing" American, "bush" British
- Sleeve bearing / plain bearing / journal bearing
- a bushing described by what it does rather than what it looks like
- Oilite
- a trade name for sintered oil-impregnated bronze (SAE 841), used generically
- Bronze-graphite / grafitado
- either graphite-plugged cast bronze or (in Brazil) simply SAE 660 – ask which
- Bearing bronze
- any bronze alloy standardised for bearings; usually means C93200 / SAE 660
- Self-lubricating bushing
- sintered, graphite-plugged or metal-polymer – never a plain cast bush
Frequently asked questions
What are the different types of bushings?
By construction: cast solid bronze, sintered oil-impregnated bronze, wrapped bronze, bimetal, graphite-plugged bronze and metal-polymer (plus plastic and rubber bushes outside the bronze family). By shape: sleeve, flanged and thrust washer. By alloy: leaded tin bronze, tin bronze, gunmetal, aluminium bronze, high-strength brass.
Is Oilite better than solid bronze?
Neither is better; they serve different duties. Sintered oil-impregnated bronze runs without relubrication at low load and small size and is cheap in volume. Cast solid bronze carries several times the load, survives shock and dirt, comes in any size and alloy and can be re-machined – but must be greased or oiled.
Are cast bronze bushings self-lubricating?
No. Solid cast bronze needs external grease or oil. Self-lubricating bronze bushes are sintered oil-impregnated or graphite-plugged types.
Which type for a pin that cannot be greased?
A graphite-plugged bronze bush for heavy load and heat, a metal-polymer bush for lighter load and higher speed. A plain cast bronze bush without lubrication will seize.
932 vs 954 – which bronze?
C93200 (932, SAE 660) for general duty on unhardened shafts with grease. C95400 (954) for twice the load, heat to 250 °C, seawater and shock – on a hardened, ground shaft with good lubrication.
Cast bronze is the right type?
See the metric size chart or send the drawing – quote in 12 hours, samples in 3 – 5 days. Not the right type? The sister sites above cover the other five.