●Specification: shaft type: round shaft; tool groove type: spiral; spiral drill diameter: 0.5 mm-2.3 mm; shaft diameter: 2.35 mm/0.09 inch; total length: 45 mm ●Material: Made of high speed steel, with high hardness and stable operation. The drill bit is titanium coated, which has a higher wear resistance and a lower coefficient of friction. Not easy to accumulate chips and long service life. ●Cooling: adapt to different types of cooling conditions, e.g. oil mist, water, oil, air cooling. ●Construction: spiral design for quick cleaning of shavings. The sharp cutting edge ensures a smooth cut without breakage. The chips cannot easily stick to the tool. ●Applications: this twist drill is right for electric drill, hand drill. Suitable for DIY resin, amber and wood drilling.