PREMIUM QUALITY - High strength heat treated tungsten steel construction, high hardness, wear resistant and lifespan is 5-10 times longer than non-tungsten faucets, and reliable for your long lasting use . EXCELLENT PERFORMANCE - Fully ground and high precision tap is ultra-sharp for your tapping and chip removal operations, running smoothly and efficiently, giving you excellent performance. ENHANCED STABILITY - Each die is designed with a locking hole, it can be locked firmly after the screw is aligned and locked, provides double stability during your operation. ADJUSTABLE TAP WRENCH - The Ta wrench is adjustable: you can set the adjustable socket wrench in its clockwise (tightening) or counter-clockwise (loosening) rotation position. You can do this by flipping the jaws 180 degrees on its pivot. SAE AND METRIC INCLUDED -This tap and die set comes with 86 pieces in total: 39 pieces, 39 pieces, 2 tap holders (M6 to M20 - 1/4" to 3/4" and M3 to M12 - 1/ 16" to 1/2"), 2 die holders (M25 - 1") and (M38 - 1-1/2") and 1 T-pin wrench, most popular sizes included. Tap & Die Sizes