Feature: 1. High Speed Steel Material: This is a twist drill with cobalt high speed steel drill bit, which is durable and has a long service life. 2. Basic Specifications: The twist drill has a precise 135 degrees bit angle, an oxidized gold finish and a round straight shank, which can prevent walking and remove chips and particles faster. 3. Heat Resistance: Twist drill alloys containing 5percent cobalt can improve heat resistance, especially when drilling hard metals. 4. Professional Use: Twist drills are very effective in cutting hard metals such as stainless steel, cast iron, high temperature alloys, titanium alloys, hard plastics and wood. 5. Satisfying Needs: Twist drills can perfectly meet your different needs and are suitable for most electric drills currently on the market. Specification: Item Type: Twist Drill Bit Material: M35 High Speed Steel Containing Cobalt Drill Bit Angle: 135 degrees Size: Diameter (Approx.) Full Length of Drill (Approx.) Working Length (Approx.) 1.5mm 0.06in 40mm 1.5in 18mm 0.7in 2mm 0.08in 49mm 1.9in 24mm 0.9in 2.5 0.1in 57mm 2.2in 30mm 1.2in 3mm 0.1in 61mm 2.4in 33mm 1.3in 3.5mm 0.14in 70mm 2.7in 39mm 1.5in 4mm 0.16in 75mm 2.9in 43mm 1.7in 4.5mm 0.18in 80mm 3.1in 47mm 1.8in 5mm 0.2in 86mm 3.3in 52mm 2in 5.5mm 0.22in 93mm 3.6in 57mm 2.2in 6mm 0.23in 93mm 3.6in 57mm 2.2in 6.5mm 0.25in 101mm 3.9in 63mm 2.5in 7mm 0.27in 109mm 4.2in 69mm 2.7in 8mm 0.3in 117mm 4.6in 75mm 3in 9mm 0.35in 125mm 4.9in 81mm 3.2in 10mm 0.4in 133mm 5.2in 87mm 3.4in . Package List: 15 x Twist Drill Bits Note: Due to manual measurement, please allow an error of 1‑2mmHigh Speed Steel Material: This is a twist drill with cobalt high speed steel drill bit, which is durable and has a long service life. Basic Specifications: The twist drill has a precise 135 degrees bit angle, an oxidized gold finish and a round straight shank, which can prevent walking and remove chips and particles faster. Heat Resistance: Twist drill alloys containing 5percent cobalt can improve heat resistance, especially when drilling hard metals. Professional Use: Twist drills are very effective in cutting hard metals such as stainless steel, cast iron, high temperature alloys, titanium alloys, hard plastics and wood. Satisfying Needs: Twist drills can perfectly meet your different needs and are suitable for most electric drills currently on the market.