7/16" Hex Shank Hole Cutter Arbor for 1-1/4" through 6" Hole Cutters Milwaukee hole saw arbors are made from hardened carbon steel and alloy steel for greater durability. The 49-56-9100 features a 7/16" Hex shank, which can be used with any 7/16" Extension. The 49-56-9100 also features a drive plate which is tightened up to the hole saw to eliminate wobble between the arbor and hole saw. Features: For 1-1/4" and Larger Arbors 7/16" Shank Since its founding in 1924, Milwaukee has focused on a single vision: To produce the best heavy-duty electric power tools and accessories available to the professional user. Today, the Milwaukee name stands for the highest quality, durable and reliable professional tools money can buy.