Diablo, 5 Pack, Steel Demon, 4'', 14/18 TPI, Metal Cutting Reciprocating Saw Blade, Full Contact Arched Edge Design Are Specifically Designed For Maximum Performance In Metal Cutting Applications, Blades Full Contact Arched Edge Design With Ultra Hardened Cutting Edge Provides Faster Cuts In Fewer Passes Resulting In Less Heat Build-Up To Deliver 5x Longer Cutting Performance Than Standard Blades, Dual Tooth Design Features A Double Tooth Configuration With Small Gullets For Faster Material Removal & Extra Durability.