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° 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 5% 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° 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 1‑2mm