Quick Change Hole Saw Arbor, Shank Size 7/16 In., Shank Shape Hex, Fits Hole Saw Dia. 1-1/4 In. and Larger, Thread Size 5/8-18, Replacement Pilot Drill No. Mfr. No. 49-56-8010, Material High Speed Steel, Pilot Drill Size 1/4 In. dia. x 3-1/2 In. L, For Use With Drill chucks 1/2 In. and larger, Includes 1 Large Thread Quick Change Arbor Milwaukee hole saw arbors are made from hardened carbon steel and alloy steel for greater durability. The 49-56-9100 features a 7/16 in. hex shank, which can be used with any 7/16 in. 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.