Easy to Use: the hexagonal head is designed to firm adsorption, and the tip of the screw is designed to be , no pre-drilling is required for operation. Perfect for use with wood, normal thickness metal, brick or other hard materials. If the electric drill is used for thicker metal layers, please keep a constant and uniform pressure. Excellent Material: the whole is made of stainless steel, which is one of the highest forms of - steel, not easy to rust, and stronger and more than ordinary materials. Exquisite workmanship, smooth thread , complete and , uniform force, not easy to slip or deform. Wide Range of Applications: This product can be used in home, industry or office. Such as fixing wooden furniture or connecting plate structures, electronic products, household appliances, fixing parts, mechanical maintenance, etc. Save time by reducing several steps in the installation process. Rich Assortment: This link contains 80 self-drilling screws and matching washers, #12 x 1 inch , #12 x 1-1/2 inch , #12 x2 inch , #12 x 2-1/2 inch , 20 pcs each. 4 lengths can be closely matched to meet your . Product Dimensions: Active Length #12 x 1 inch is 25mm, #12 x 1-1/2 inch is 32mm, #12 x2 inch is 50mm, #12 x 2-1/2 inch is 63.5mm. the detailed dimensions are shown in the picture. Material: Stainless steel colour: silver Package Contents: 1 set x screws assortment Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.