Here you will find a cross reference between MM and Inches.
| MM | Approx Inches |
|---|---|
| 100 | 4" |
| 110 | 4 1/4" |
| 115 | 4 1/2" |
| 120 | 4 3/4" |
| 125 | 5" |
| 135 | 5 1/4" |
| 140 | 5 1/2" |
| 145 | 5 3/4" |
| 150 | 6" |
| 160 | 6 1/4" |
| 165 | 6 1/2" |
| 175 - 180 | 7" |
| 185 - 190 | 7 1/2" |
| 200 | 8" |
| 254 | 9" |
| 250 | 10" |
| 275 | 11" |
| 300 | 12" |
| 325 | 13" |
| 350 | 14" |
| 400 | 16" |
| 450 | 18" |
| 500 | 20" |
| 600 | 24" |