Precision ground, super-efficient bi-metal blade that is faster and lasts longer on tough materials. The high-speed steel cutting edge is welded to a tough alloy steel back that provides optimum tool life together with a high resistance to breakage. Blade cross section 13 x 0.65 mm (1/2 x 0.025 Inch). Blade length: 300mm (12in).50 x Starrett ;Bi-Metal Unique Safe-Flex Hacksaw Blades 300mm (12in) x 18tpiAdditional Information:• Type: Blade• TPI: 18• Pack Qty.: 50