Morse MA45PSNCT (139847), spring loaded arbor provides a 7/16" solid shank can be used with any standard hole saw with 5/8"-18 thread pitch (1-1/4" to 6-5/8" diameter). The strength of the spring ensures the arbor pins remain engaged during use, effectively handling the torque generated by larger diameter hole saws, preventing thread strippage. Easily change hole saw diameters with efficiency and minimal effort. Carbide tipped pilot drill for use in masonry and abrasive applications. One (1) arbor per box.