Variable depth gullets-provide more efficient chip removal. ^ High-speed cutting steel edge-for stronger teeth, longer life. ^ Bi-Metal construction-for toughness and long life. ^4/6 Pitch variable teeth-for reduced noise and improved performance. ^ contains: Bi-Metal 5/8" 3/4" 7/8" 1" 1 - 1/8" 1 - 1/4" 1 - 3/8" 1 †“ 1/2" 1 - 3/4" 2" 2 - 1/2" 3" Hole Saw 3/8 Hex Shank Arbor 1/2 Hex Shank Arbor Y 3 Pilot bits packaged in a fitting case.