Irwin  Hanson  High Carbon Steel  5/16 in. *Sub Brand: Hanson *Material: High Carbon Steel *Diameter: 5/16 in.-18NC *Metric or SAE: SAE *Product Type: Fraction Tap *Number in Package: 1 pc. *Packaging Type: Carded *Ideal for routine maintenance, repair work and for rethreading where high accuracy and tolerance thread is not critical *Straight flutes are ground to provide rapid chip removal for efficient threading *Designed for hand threading work in a variety of materials *Taps produce a class 2B thread *Discovery CON, NBR, SUP, EXP