Incorrect there are sets of drill bits or indexes that use a letters and numbers style of sizing...that being said I have not seen these at Harbour Freight
Drill bits come in sizes not numbers and letters. If you are referring to number and letter punches they do have those in assorted sizes.
I bought my set of bits there. 3 sets in 1. Fractional, number, and letter bits. With a size chart and a very nice case actually.
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