WEN LA4374 3.75-Inch 4-Jaw Self-Centering Lathe Chuck Set with 1-Inch x 8TPI Thread. Only 10 left in stock - order soon. FREE Shipping on eligible orders. 4.1 out of 5 stars 12. See more choices. PSI Woodworking LA341018 Headstock Spindle Adapter (3/4-Inch x 10tpi to 1-Inch x 8 tpi chuck) by PSI Woodworking. More Buying Choices.