Twist Drill Bit Kit KangTeer 13pcs 2-12mm High-Speed Steel Titanium Plated Drill Bits HSS Woodworking Wood Plastic Aluminium Drilling Tool: Industrial & Scientific. Twist Drill Bit Kit KangTeer 13pcs 2-12mm High-Speed Steel Titanium Plated Drill Bits HSS Woodworking Wood Plastic Aluminium Drilling Tool: Industrial & Scientific. Made of high speed steel 4241 and coated with titanium for rust prevention. 。 Processing of titanium coating with overall quenching, which has high hardness 。 Mainly used for drilling wood and plastic, occationally for drilling soft metal like aluminium. Economic choice for home DIY, building and engineering use etc. 。 It includes 13 sizes metric twist drill bits in one set(2mm, 2.5mm, 3mm, 3.2mm, 4mm, 5mm, 5.5mm, 6mm, 8mm, 8.5mm, 10mm, 10.5mm, 12mm) 。 Affirms: In case of any quality problem within 3 months, we support a full refund (no return required) 。 They are made of high-speed steel 4241. There are several commonly-used HSS types: 4241, 4341, M2, M3, M42. HSS 4241 is of the lowest price and relatively lower quality compared to others. 。 The material decides that they can be used mainly in drilling wood, plastic and soft metal sheet like aluminum. 。 If your purpose is to drilling metal, please buy M3 grade drill bits.。 。 Shank: Round。 Material: High-speed steel 4241。 Surface Treatment: Plating titanium。 Package include:。 13 * Twist Drill Bit。 。 。 。