Lathe Chuck Backplate Adapters
The first rule of buying a threaded adapter is to measure the threads on your spindle. There are simply too may variants of every kind of lathe to trust any chart.
If your lathe is listed below, it's easy to find the correct backplate adapter. If your lathe is not listed, measure the spindle threads and find the same thread in the table below.
We make no guarantees on the accuracy of this information.
MEASURE YOUR SPINDLE.
| Lathe | Chuck Diameter | ||||||
|---|---|---|---|---|---|---|---|
| Brand | Model | Swing | Thread | 3" | 4" | 4" (3-jaw) | 6" |
| Atlas | 109 | 6" | 1/2"-20 | Use 2022 | |||
| Atlas | 101 | 6" | 1"-10 | Use 1791 | 1791 | 1917 | |
| Atlas | 101.07 | 6" | 1"-8 | Use 1790 | 1790 | 1916 | |
| Atlas | TH42 | 10" | 1 1/2"-8 | Use 1792 | 1792 | 1918 | 1919 |
| Atlas | 5991 | 12" | 1 1/2"-8 | Use 1792 | 1792 | 1918 | 1919 |
| Atlas | 3986 | 12" | 1 1/2"-8 | Use 1792 | 1792 | 1918 | 1919 |
| Craftsman | AA109 | 6" | 1/2"-20 | Use 2022 | |||
| Craftsman | AA109 | 6" | 1"-10 | Use 1791 | 1791 | 1917 | |
| Craftsman/Atlas | 101.07 | 6" | 1"-8 | Use 1790 | 1790 | 1916 | |
| Craftsman/Atlas | 101.21 | 6" | 1"-10 | Use 1791 | 1791 | 1917 | |
| Craftsman/Atlas | 101.28 | 12" | 1 1/2"-8 | Use 1792 | 1792 | 1918 | 1919 |
| Craftsman/Dunlap | 109 | 6" | 1/2"-20 | 2022 | |||
| Emco Maier | Maximat V10 | 5" | M39x4mm | Use 1921 | 1921 | Use 1921 | 1922 |
| Grizzly | G8688 | 7" | 3" Flange | None | 1692 | 1692 | |
| Grizzly | G4000 | 9" | M39x4mm | Use 1921 | 1921 | Use 1921 | 1922 |
| Harbor Freight | 33684 | 7" | 3" Flange | None | 1692 | 1692 | |
| Harbor Freight | 45861 (BV20) | 9" | M39x4mm | Use 1921 | 1921 | Use 1921 | 1922 |
| Homier | 03911 | 7" | 3" Flange | None | 1692 | 1692 | |
| Jet | 920N | 9" | 1 1/2"-8 | Use 1792 | 1792 | 1918 | 1919 |
| King | CH-920 AG | 9" | M39x4mm | Use 1921 | 1921 | Use 1921 | 1922 |
| Logan | 9" | 1 1/2"-8 | Use 1792 | 1792 | 1918 | 1919 | |
| Logan | 10" | 1 1/2"-8 | Use 1792 | 1792 | 1918 | 1919 | |
| Logan | 11" | 2 1/4"-8 | Use 1923 | Use 1923 | Use 1923 | 1923 | |
| Logan | 12" | 2 1/4"-8 | Use 1923 | Use 1923 | Use 1923 | 1923 | |
| Logan | 6510/6560 | 14" | 2 1/4"-8 | Use 1923 | Use 1923 | Use 1923 | 1923 |
| Micro-Mark | 82710 | 7" | 3" Flange | None | 1692 | 1692 | |
| Micro-Mark | 82500 | 7" | 3" Flange | None | 1692 | 1692 | |
| Sheldon | WM-46-P | 13" | 2 1/4"-8 | Use 1923 | Use 1923 | Use 1923 | 1923 |
| Sherline | All | 3.5" | 3/4"-16 | 1920 | |||
| Sidney Machine | Lot 160 | 14" | 2 1/4"-8 | Use 1923 | Use 1923 | Use 1923 | 1923 |
| South Bend | CL187ZB | 10" | 2 1/4"-8 | Use 1923 | Use 1923 | Use 1923 | 1923 |
| South Bend | CL8187AB | 10" | 2 1/4"-8 | Use 1923 | Use 1923 | Use 1923 | 1923 |
| Taig | Microlathe II | 4.5" | 3/4"-16 | 1920 | |||
If you have updated information on spindle threads, please let us know.