MUXSAM 19Pcs/Set High Speed Steel Titanium Coated HSS 4241 Drill Bit Metric 1mm-10mm Material: HSS 4241. Surface treatment: Titanium (Gold) The surface has been titanized, sharp edge, high hardness, good toughness, quick cutting speed, long service life, durable. The craft work of 135 degree apex angle and double apex angle enhanced friction force, not easy slip, work efficiently. The suitable tools are electric hand drill and impact drill, applicable for punching on angle iron, wood, plastic, metal sheet, iron sheet and other materials, do not apply to thick steel plate. 19 Sizes: 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm