This is a nice Reamer Bit. Reamer engraved with 5/16, mics .312. This is Straight 6 Flute Stock #0186. This reamer is 4 1/8” long. I am selling out the contents of a machine shop so be sure and check out my other listings for other Machine Shop type items. I am listing all the Reamers as used even though a lot of them look new!!!!                         I am offering FREE SHIPPING to the lower 48 states. This is being sold AS IS