Bushing size calculator
Start from the shaft. The calculator returns the standard bushing sizes for that diameter in every construction we make, the length the load needs in each material, and the housing, shaft and bushing tolerances with the resulting interference and clearance. Sizes off the standard series are made to drawing.
A bushing is sized bore × outside diameter × length, and the bore is the shaft. From the shaft diameter the standard series fix the rest: ISO 4379 gives three outside diameters (thin, medium, thick wall) and standard lengths for machined bronze; the ISO 3547 strip series gives one thin wall (1–2.5 mm) shared by wrapped bronze, PTFE and POM composite and bimetal bushings. Enter the load to see how long the bushing must be in each material, and the space in the housing to flag sizes that will not fit.
Sizes for this shaft
- Machined bronze, medium wall (ISO 4379)
- Thin-wall strip series (ISO 3547)
- Length range L = 0.5–1.5 d
- Specific load at the size above
Standard sizes by construction
Every row is made to order; “standard” means the size is in the published series and ships fastest. Use the size charts for the full tables.
Length the load needs, by material
L required = F ÷ (p allowable × d), using the moving (dynamic) load limit published for each material. Keep L between 0.5 and 1.5 d; if a material needs more, choose a stronger material or a larger shaft.
Fits for this size
ISO 286 deviations in µm (upper / lower). Machined bronze: OD s6 / r6 in an H7 housing, bore about H8 after fitting against an e7 shaft. Strip series: catalogue oversize OD in an H7 housing, f7 shaft (h8 for bimetal); the installed bore and clearance are in the size charts.
The interference and clearance shown are the min–max of the whole tolerance stack; check the fitted bore on the first-off part. Use the press-fit calculator for other tolerance classes.
Sizes appear here. A link to quote the size follows.Quote this size →
How the sizes are chosen
Machined bronze follows ISO 4379 (formerly DIN 1850): for each of 46 bores from Ø6 to Ø200 mm the standard lists three outside diameters, a thin, a medium and a thick wall, and two or three lengths. The calculator picks the row for your shaft, or the nearest larger bore when the shaft is not a standard size, and proposes the medium wall with the standard length nearest to L = d. Any other bore, wall or length is machined to drawing, Ø3–1000 mm, in C93200 or another alloy.
The thin-wall constructions share the ISO 3547 dimension system: the wall is 1.0 mm up to Ø18–20, 1.5 mm to Ø28, 2.0 mm to Ø40 and 2.5 mm from Ø45, so the outside diameter is the shaft plus 2, 3, 4 or 5 mm. Wrapped bronze (Ø10–300), PTFE composite (Ø6–300) and bimetal (Ø10–150) each publish their own list of standard bores and lengths; the calculator looks your shaft up in each list and marks the size standard or to drawing.
How long should a bushing be?
Between half and one and a half times the bore. Shorter than 0.5 d the bushing tilts in the housing and wears at the edges; longer than 1.5 d the ends carry the load because no shaft is perfectly straight, and the middle does nothing. Within that range the load sets the length: L = F ÷ (p × d), where p is the moving load limit of the material. A 40 mm shaft carrying 12 kN needs 12 000 ÷ (25 × 40) = 12 mm of greased cast bronze, 7.5 mm of wrapped bronze or 2 mm of bimetal; in practice you take L ≈ d for alignment and stiffness and let the low specific load buy life. When the required length exceeds 1.5 d, the material is too weak for the shaft: move to a stronger material or a larger shaft.
The fits behind the numbers
Machined bronze: the outside diameter is s6 up to Ø120 mm and r6 above, the housing is H7, and the interference that results holds the bushing and closes its bore from E6 to about H8. Against an e7 shaft the running clearance at Ø40 is 50–114 µm. Thin-wall wrapped bushings are made oversize by the catalogue amount for an H7 housing; their bore reaches the installed value in the size chart after pressing, and the shaft is f7 (wrapped bronze, PTFE) or h8 (bimetal). The calculator shows the H7 housing bore for both constructions and the e7 and f7 shafts, so the drawing can be completed from one screen.
Put bore × OD × length, the construction and the fit classes on the enquiry; we quote against the fit stated.
Inch shafts
Switch the units to inch and enter the shaft in decimal inches; the calculator converts to millimetres, looks up the metric standard series and displays the results in inches. There is no inch equivalent of ISO 4379 or ISO 3547; inch bushings are machined to the drawing in the same alloys, so a standard metric size is only useful if the housing can be bored to it. Send inch drawings in inches with the fit; do not convert.
What the calculator does not do
It does not check speed or PV (use the plain bearing PV calculator), estimate wear life or temperature, or size a flange or thrust washer. It does not know the housing material: aluminium and plastic housings need more interference or a mechanical stop for thin-wall bushings. And the standard series is not a stock list; every size is made to order and confirmed at quotation, with samples free and no minimum order.
Frequently asked questions
How do I determine the bushing size for a shaft?
The bore equals the shaft diameter. The outside diameter follows from the construction: ISO 4379 lists three walls for machined bronze, the ISO 3547 strip series one wall of 1–2.5 mm for wrapped bronze, composite and bimetal. Take the length between 0.5 and 1.5 times the bore, checked against the load with L = F ÷ (p × d).
What is a standard bushing wall thickness?
Strip bushings: 1.0 mm to about Ø20, 1.5 mm to Ø28, 2.0 mm to Ø40, 2.5 mm from Ø45. Machined bronze to ISO 4379: about 1–1.5 mm (thin), 2–5 mm (medium) and 3–10 mm (thick) depending on the bore, and any wall to drawing.
How long should a bushing be relative to its bore?
Between 0.5 and 1.5 times the bore, with L ≈ d as the usual choice. The load sets the minimum: L = F ÷ (p allowable × d).
What tolerance should the housing bore be?
H7 for every construction. The bushing outside diameter carries the interference: s6 / r6 for machined bronze to ISO 4379, a catalogue oversize for wrapped bronze, composite and bimetal bushings.
My shaft is not a standard size. Can you still make the bushing?
Yes. Every size is made to order; the standard series only ships faster. Send bore × OD × length with the construction and fit, or the drawing. There is no minimum order and samples are free.
Quote the size, or send the drawing.
Bore × OD × length with the construction and the fit. Standard and non-standard sizes are made to order; samples are free.