These bits are precision ground to give you precise, perfectly round holes in any type of wood. From the hardest of hardwoods to the softest, these bits will will get the job done. They will also make a perfectly flat bottom hole if you need to drill blind holes. Made of high speed steel, these can take the everyday abuse of the industrial workplace, but at an unbelievable price anyone can afford.This set comes complete with a huge 23x9x4 wooden box for keeping all of the bits neatly in order for quick retrieval when you need one. This set ranges from 1/4" to 3-1/8" by 1/8" increments giving you any and all sizes you may need. All bits over 1" has a extra large diameter body for extra strengh. Bits 2-1/8" and down have a 3/8" shank. All Above 2-1/8 has 1/2" shank. Whether its woodworking, cutting holes for plumbing or electrical work, this set will have the size you need.