Logan Lathe 820, Tail Stock Screw / Key, Part # LA-146, 7/16" - 10 Left Hand Thread, Hand Wheel Retainer Thread is 3/8"- 24, OAL 5 - 5/16".  - Questions and Comments are Welcome, Thanks for Looking

 
Note: If you're looking for 7" x 10" Mini Lathe parts that I don't have listed, contact me, all I need is a part number and I can give you a price quote. Thanks