Starrett straight 6-pitch hole saw. Hardened, heat resistant HSS, with alloy backing and a straight 6-pitch smoothly cuts thin cross sections of sheet metal, corrugated or perforated steel, and applications with interrupted cuts. 1-5/8-inches cutting depth. Provides a smooth cut, with minimal tendency to bite or snag on contact with irregular surfaces. Constructed of hardened steel and abrasion resisting high speed steel teeth with a tough alloy body and cap. Six teeth per inch/25mm make this saw ideal for thinner gauge materials. 2-1/2-inches diameter. A2 or A10 arbor type. 5/8"-18 thread size.