Whiteside Screw Type Helix Mortise Cutter w/Downshear, 41/64 in. CD is designed specifically to create precise hinge mortises with ease. This versatile helix mortise cutter can be used with either handheld or machine routers, making it a practical choice for various woodworking applications. Featuring a down shear cutting design, it ensures clean, splinter- cuts for a professional finish every time. The cutter includes a 1/4-28 internal thread size and requires a 1/4" or 1/2" shank Helix Mortise Arbor (HMA14 or HMA12), which are sold separately. This 2-wing carbide tipped cutter is manufactured by Whiteside Machine Company in Claremont, North Carolina, and a cutting diameter of 41/64", cutting length of 5/8", and an overall length of 7/8". Model Number: 13-640