Three-jaw Manual Chuck Clamping Range – Complete Size Reference Chart
The jaws of a three-jaw chuck are divided into internal jaws and external jaws.
The clamping range for both outer diameters and inner bores varies depending on the chuck’s overall diameter.
Below is a reference chart showing the clamping ranges of TOP-TOOL three-jaw manual chucks across different chuck sizes.
Please note that the clamping range is independent of the chuck’s spindle mounting type — whether you are using a short taper mount chuck or a plain-back chuck with a flange adapter, this chart still applies.
⚠️ Important:
If you need to clamp a workpiece that is too large or too small for the specified range:
-
We do not recommend expanding internally or clamping a workpiece that exceeds the chuck’s outer diameter, as this may cause cracks in the T-slot connecting the jaws and the chuck body.
-
If your workpiece is smaller than the minimum clamping range, we can provide custom, non-standard jaws designed specifically for your application.
| Chuck Diameter D | External Jaw Clamping Range A-A1 |
External Jaw Expanding Range B-B1 |
Internal Jaw Clamping Range C-C1 |
|---|---|---|---|
| 80 | 2-22 | 25-70 | 22-63 |
| 100 | 2-30 | 30-90 | 30-80 |
| 125 | 2.5-40 | 38-125 | 38-110 |
| 130 | 3-40 | 40-130 | 40-120 |
| 160 | 3-55 | 50-160 | 55-145 |
| 165 | 4-60 | 52-165 | 55-150 |
| 190 | 4-70 | 65-190 | 65-190 |
| 200 | 4-85 | 65-200 | 65-200 |
| 240 | 6-100 | 80-250 | 90-250 |
| 250 | 6-110 | 80-250 | 90-250 |
| 315 | 10-140 | 95-315 | 100-315 |
| 320 | 11.5-145 | 95-320 | 110-320 |
| 325 | 11.5-165 | 95-350 | 110-340 |
| 380 | 11.5-210 | 95-400 | 110-400 |
| 400 | 15-210 | 120-400 | 120-400 |
| 500 | 25-280 | 150-500 | 150-500 |
| 630 | 50-350 | 170-630 | 170-630 |