Alloy four-edged crossdrill, sharping and long-lasting, fast drilling, versatile and accurate hole punching. Sharping drilling edges, high toughness, abrasion resistance, high density hardness, and nice adaptability. Widened spiral texture, smooth chip removal, faster chip removal when operating and using. Hexagonal drill shank with high compatibility, suitable for lithium drill, electric drill, table drill and other power tools on the market.  Specifications: Name: Drill Bit Set Material: alloy Type: 10pcs 4mm bits, 10pcs 6mm bits (optional) Shank diameter: 6.3mm Package size: 100 * 50 * 30mm / 3.94 * 1.97 * 1.18in Package weight: 150g / 5.29ounce Packing List: 10 * Drill Bits