New Jacobs chucks holds upto 3/8" drill shanks. 1 has a 3/8-24 adaptor thread, attaches to dewalt black & decker and so on hand drills. The open item Jacobs No. 30 has a Jt2 taper for drill presses/Morse taper adaptor. Open item has a box, chuck is new old stock but key is used. Stamped made in "The United States of America"
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