VEVOR 3-Jaw Lathe Chuck, 10'', Self-Centering Lathe Chuck, 0.24-9.84 in/6-250 mm Clamping Range with T-key Fixing Screws Hexagon Wrench, for Lathe 3D Printer Machining Center Milling Drilling Machine

Mine took a 1-1/2 8tpi

There is no back plate on the Chuck!You have to buy it separately.You would most likely have to machine it to fit the Chuck!

It's only meant to bolt onto a vevor mini lathe so there is no backplate you can buy unless it's a replacement part for the mini lathe which is a custom size. Mine wasn't a replacement per say so I had to measure and fabricate one for my use. I believe I 3d printed a thin mock up first because if I recall the bolt patt… see more It's only meant to bolt onto a vevor mini lathe so there is no backplate you can buy unless it's a replacement part for the mini lathe which is a custom size. Mine wasn't a replacement per say so I had to measure and fabricate one for my use. I believe I 3d printed a thin mock up first because if I recall the bolt pattern is different distances on the three mount holes then I ported it to an nc file. If you don't have a CNC mill or router you could also use an online service like xometry once you get it drawn up just make sure you check their dimensions. As sometimes they screw up with the dimension ratio depending on what CAD software you are using. see less It's only meant to bolt onto a vevor mini lathe so there is no backplate you can buy unless it's a replacement part for the mini lathe which is a custom size. Mine wasn't a replacement per say so I had to measure and fabricate one for my use. I believe I 3d printed a thin mock up first because if I recall the bolt pattern is different distances on the three mount holes then I ported it to an nc file. If you don't have a CNC mill or router you could also use an online service like xometry once you get it drawn up just make sure you check their dimensions. As sometimes they screw up with the dimension ratio depending on what CAD software you are using.