Custom Bushings in Aluminum, Bronze & Steel

Which kind of bushing is on the print?

Split, grooved and drill bushings are quoted to the print like any sleeve. The shape decides what the print has to carry beyond the bore, the OD and the length.

Drill bushings, fixture bushings and small slender bushings

Standard inch drill bushings are sized to ASME B94.33, and a custom one covers what the standard does not. When two holes sit too close together for separate standard bushings, one larger bushing can carry both holes, or a bushing with an eccentric hole can be located by notches in its head (source 2). The jig itself is covered under drill and trim jigs, and the SPC bushings in a check fixture under check and inspection fixtures.

Small, slender bushings are often quoted as Swiss screw machining, where the tools cut in front of a guide bushing and the bar is held firmly, with little chance of deflection (source 3).

Some bushings belong with the part they serve. A pump shaft sleeve, throat bushing or wear ring is covered with machined pump parts, which list the materials and fits a pump print usually names, and a rebuild shop reordering throat and line-shaft bushings pump after pump can start on pump and motor repair parts. A die button that pairs with a pierce punch is quoted with the punch, so the clearance between them is set together. A sleeve that carries no load and only sets a distance is a spacer, and standoffs and spacers covers odd lengths, clearance diameters and threads. A sleeve for re-sleeving a worn motor end bell or bearing housing bore is on bearing housing sleeves.

How much press fit, and what happens to the bore?

A press fit makes the bushing slightly larger than its housing bore: ISO H7/p6 is a light interference fit assembled by cold pressing, and bushings are among its listed uses. The bore gets a clearance fit instead, such as H7/g6 where the shaft has to turn and slide freely with minimal clearance, or H8/f7 for a close running fit at moderate speeds (source 4).

Engineers Edge describes bushings up to 3 in made 0.002 to 0.003 in over nominal on the OD, and 0.003 to 0.005 in over above 3 in. Pressing one in shrinks its bore by 70 to 100 percent of the interference, a change it says cannot be predicted precisely, which is why bushings are often made with extra material in the bore and reamed to size after they are installed (source 5).

Where the bore needs a finer finish or a more accurate size than turning leaves, it can be ground on the inside diameter (source 6). Precision grinding covers ID grinding.

Which material for a bushing or sleeve bearing?

A common plain bearing design pairs a hardened, polished steel shaft with a softer bronze bushing, which is replaced when it has worn too much (source 1), and brass and bronze are often chosen for bushings and other sliding parts for their resistance to galling (source 7). Bronze bushings are quoted in C93200, also termed C932 or SAE 660 bearing bronze, which Wieland Concast lists for bushings and pump bushings (source 8), and in C95400 aluminum bronze, listed for bearings, bushings and gears (source 9).

SAE 841, a sintered, oil-impregnated bronze, is quoted as well. Oilite, one brand of it, is made by powder metallurgy from copper with about 10 percent tin, its pores vacuum-impregnated to hold at least 19 percent oil by volume, and SAE 841 is among the standards that cover it (source 10). Machining it takes a tool that stays sharp, reaming is not recommended, and grinding or honing a surface the shaft runs on smears the pores shut (source 10). So for an SAE 841 bushing, put the bore you need after pressing and the housing bore on the print, rather than a bore left undersize to ream (sources 5 and 10).

Aluminum (6061) galls very easily (source 7). Anodizing makes the surface harder than bare aluminum, with low to moderate wear resistance that improves as the coating gets thicker, and its pores retain a lubricating film better than a smooth surface would; Type III hard anodize is the thick end, over 0.001 in (source 11). Stainless resists rust and corrosion (source 12). Steel and tool steel bushings are quoted to the grade on the print; the steel page covers the grades.

Plastic sleeve bearings are light, resist corrosion and run without maintenance (source 1). Delrin, or acetal, is stiff, low in friction and dimensionally stable (source 13), and PEEK is on the same list of common bearing plastics as nylon, PTFE and UHMW polyethylene (source 1). Other alloys and plastics quoted on request. Name the grade on the print.

No C of C or material certifications ship with parts by default. If your PO needs them, say so before the quote. Inspection reports on critical dimensions aren’t included by default. If you need one, ask when you place the order.

What should the print or RFQ say?

Give the housing bore the OD presses into, or the fit class, so the interference is quoted to your housing.

Say whether the bore on the print is the size as made, or a bore left undersize to ream after the bushing is pressed in. Sintered bronze is the exception noted above.

If the bore has to run true to the OD, put a runout callout between them; circular runout covers the combined error of roundness and coaxiality (source 14). Position, perpendicularity and runout callouts are quoted from the print.

Name the material grade. If it is not chosen yet, pick “Not sure - please advise” on the quote form, say what the shaft is made of and what the bushing does, and the quote suggests a material.

Name the finish, if any, and say whether the bore and OD sizes apply before or after it. A finish called out on the print is quoted with the part. Anodizing grows the oxide into and out of the surface by equal amounts (source 11).

Sources

All accessed 27 September 2026. Where a figure here differs from your print, the print governs.

1. Wikipedia, "Plain bearing": en.wikipedia.org/wiki/Plain_bearing (sleeve, flanged and split bushings; the flange locates or takes thrust; grooves carry lubricant; hardened steel shaft in a softer bronze bushing, replaced when worn; polymer bearings light, corrosion resistant, maintenance free; common bearing plastics).

2. Wikipedia, "Drill bushing": en.wikipedia.org/wiki/Drill_bushing (guides a drill in a jig; inch sizes standardized in ASME B94.33; a two-hole or eccentric-hole custom bushing where holes are too close for standard ones).

3. Wikipedia, "Metal lathe", section "Swiss-style lathe / Swiss turning center": en.wikipedia.org/wiki/Metal_lathe (tools in front of the guide bushing; slender workpieces held firmly with little chance of deflection).

4. Wikipedia, "Engineering fit": en.wikipedia.org/wiki/Engineering_fit (H7/p6 press fit, light interference by cold pressing, e.g. bushings; H7/g6 sliding fit; H8/f7 close running fit).

5. Engineers Edge, "Bushing and Plain Bearings Press or Shrink Fit Design and Application": engineersedge.com (OD over nominal by size; diameter change 70 to 100 percent of the interference, not precisely predictable; reaming after installation).

6. Wikipedia, "Grinding (abrasive cutting)": en.wikipedia.org/wiki/Grinding_(abrasive_cutting) (internal grinding of the inside diameter; very fine finishes and very accurate dimensions).

7. Wikipedia, "Galling": en.wikipedia.org/wiki/Galling (aluminium galls very easily; stainless particularly susceptible; same or different metals; brass and bronze chosen for bushings for galling resistance).

8. Wieland Concast, "C93200 Leaded Tin Bronze": concast.com/c93200.php (also termed C932, Bearing Bronze and SAE 660; bushings and pump bushings among its applications).

9. Wieland Concast, "C95400 Aluminum Bronze": concast.com/c95400.php (aluminum bronze; the highest strength standard copper-based alloy; bearings, bushings, gears).

10. Wikipedia, "Oilite": en.wikipedia.org/wiki/Oilite (powder metallurgy; copper with about 10% tin; minimum porosity 19% oil by volume; SAE 841; sharp tools; reaming not recommended; no grinding or honing on the journal surface).

11. Wikipedia, "Anodizing": en.wikipedia.org/wiki/Anodizing (harder than aluminium, low to moderate wear resistance improved by thickness; pores retain a lubricating film; Type III over 25 μm, 0.001 in; oxide grows into and out of the surface by equal amounts).

12. Wikipedia, "Stainless steel": en.wikipedia.org/wiki/Stainless_steel (resistant to rust and corrosion; galling mitigated with dissimilar materials, bronze against stainless, or martensitic against austenitic).

13. Wikipedia, "Polyoxymethylene": en.wikipedia.org/wiki/Polyoxymethylene (high stiffness, low friction, excellent dimensional stability; sold as Delrin).

14. George Schuetz, "TIR Versus Concentricity For Coaxiality", Modern Machine Shop, 3 April 2005: mmsonline.com/columns/tir-versus-concentricity-for-coaxiality (circular runout controls the total of circularity and coaxiality variation).