Machine (machinery) bushings by shaft size: the outside diameter of narrow rim and wide rim bushings, and the thickness of 10, 14 and 18 gauge.
A machine bushing is a precise flat steel washer that slips over a shaft. It is used to take up end play, to space sprockets, pulleys and gears accurately on a shaft, and to keep moving parts from wearing on each other. A bushing is sized by the shaft it fits (its nominal inside diameter), its outside diameter — narrow rim or wide rim — and its gauge (thickness).
Jump to: Gauge thickness · Narrow rim · Wide rim
| Gauge | Class | Thickness (min) | Thickness (max) |
|---|---|---|---|
| 10 ga | heavy | .126 | .142 |
| 14 ga | medium | .068 | .082 |
| 18 ga | light | .042 | .054 |
| Fits shaft | OD |
|---|---|
| 1/2″ | 7/8″ |
| 9/16″ | — |
| 5/8″ | — |
| 3/4″ | 1-1/4″ |
| 7/8″ | 1-3/8″ |
| 1″ | 1-1/2″ |
| 1-1/8″ | 1-3/4″ |
| 1-1/4″ | 1-7/8″ |
| 1-3/8″ | 2-1/8″ |
| 1-1/2″ | 2-1/4″ |
| 1-5/8″ | 2-3/8″ |
| 1-3/4″ | 2-1/2″ |
| 1-7/8″ | 2-7/8″ |
| 2″ | 3″ |
| 2-1/8″ | 3-1/8″ |
| 2-1/4″ | 3-1/4″ |
| 2-1/2″ | 3-1/2″ |
| Fits shaft | OD |
|---|---|
| 5/8″ | 1-1/4″ |
| 3/4″ | 1-1/2″ |
| 1″ | 2″ |
| 1-1/8″ | 2-1/8″ |
| 1-1/4″ | 2-1/4″ |
| 1-3/8″ | 2-1/2″ |
| 1-1/2″ | 3″ |
| 1-5/8″ | 3-1/8″ |
| 1-3/4″ | 3-1/4″ |
| 2″ | 3-1/2″ |
Good to know
Gauge is the thickness, not the shaft size: 10 gauge is the heaviest and 18 gauge the lightest. Stack bushings of different gauges to reach the spacing you need.
Narrow or wide rim is the outside diameter: the same shaft size comes in both, and the wide rim covers more face.
Spacing and wear: machine bushings take up end play, set accurate spacing on a shaft and keep moving parts from wearing on each other or marring a finish.
Not on this chart: sizes only one of our sources lists (narrow rim 2-3/8; wide rim 7/8, 15/16, 1-7/8, 2-1/8, 2-1/4, 2-1/2, 3) and quick repair washers. Their TECH DATA sheets give the part’s listed size.
Quick answers
- How thick is a 14 gauge machine bushing?
- A 14 gauge (medium) machine bushing is .068–.082″ thick; 18 gauge (light) is .042–.054″ and 10 gauge (heavy) .126–.142″.
- What is the OD of a 1 inch machine bushing?
- A 1″ narrow rim machine bushing is 1-1/2″ OD; a 1″ wide rim bushing is 2″ OD.
- What is the difference between a narrow rim and a wide rim machine bushing?
- Both fit the same shaft size and come in the same gauges; a wide rim bushing has a larger outside diameter, so it covers more face (at 1″: 1-1/2″ narrow, 2″ wide).
- Which machine bushing gauge is the thickest?
- 10 gauge (heavy), .126–.142″ thick. The bigger the gauge number, the thinner the bushing.