I'm am looking for a replacement chuck for my Sear's 3/8" corded drill model #315.271.490. I would prefer to put in a keyed replacement. Sears will only sell me a keyless chuck. Where could I find an appropriate chuck for this 1/2" shafted drill? Is there a particular thread type I need to be look for?

I would check out Jacobs website. They make the best keyed chucks. They can also tell you which one you need for your drill. http://www.jacobschuck.com/default.asp

Good Luck

Home depot sell both types