【8 DIFFERENT SIZE】: Twist drill bits come in 8 kinds of diameters, 4 4.2 4.5 5 5.2 6 8 10mm, different hole sizes to meet your needs 【HIGH QUALITY MATERIAL】: Our twist drill bits are made of HSS 4241 high speed steel, full milling process, for high hardness and durability 【ULTRA-LONG】: The extra-long cutting edge of total 200 mm allows you to use these drill bits to drill deep holes 【ADVANTAGE】: Accurate positioning, fast cutting, strong chip removal, good wear resistance, sharp twisted drill bits will make drilling easier and easier. 【WIDE USE】: HSS drill bit is suitable for steel castings, spring steel, white steel, ordinary steel, angle iron, aluminum, copper, wood and stainless steel 1-4 mm, etc., drilling various materials HSS Twist Drill Bit Set Round Shank Ø 4-10mm, Drilling Tools 200mm Length for Wood, Metal and Steel Features: - Twisted spiral design, easy to remove sawdust, iron filings at work. - 8 different diameters available 4mm, 4.2mm, 4.5mm, 5mm, 5.2mm,