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 or 1774	1692 or 1774
Grizzly	G4000	9"	M39x4mm	Use 1921	1921	Use 1921	1922
Harbor Freight	33684	7"	3" Flange	None	1692 or 1774	1692 or 1774
Harbor Freight	45861 (BV20)	9"	M39x4mm	Use 1921	1921	Use 1921	1922
Homier	03911	7"	3" Flange	None	1692 or 1774	1692 or 1774
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 or 1774	1692 or 1774
Micro-Mark	82500	7"	3" Flange	None	1692 or 1774	1692 or 1774
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.