Suitable for the following metals: Aluminium, Aluminium Alloy, Copper, Platinum, Silver, Gold, Titanium, Zinc, Alloys, Chrome, Tin, Aluminium Profile, Steel/Ferrous Metal, Unalloyed/Low-Alloy Steel, High-Alloy Steel and Gray Iron. The Bosch 2608596816 Pack Of 5 have a 4.0mm diameter, a working depth of 78mm and an overall length of 119mm. The HSS Twist Drill Bit Ground is for drilling through metal with maximum precision. The bit\'s exposed 135-degree self-centring split-point tip combines active cutting and perfect centring without wandering, delivering maximum precision. The split-point tip also eliminates any need to pre-punch or pilot drill for up to 10 mm. This precision-ground bit made of HSS (high-speed steel) enables up to 40% faster drilling rate and up to 50% lower feed pressure than standard-ground HSS drill bits with chisel edges. This bit is designed for drilling holes in alloyed and non-alloyed steel, cast steel, cast iron, sintered iron, malleable cast iron, non-ferrous metals and hard plastics. It has a cylindrical shank system (shank equal to drill bit diameter) and is intended for use in drill stands and drill drivers. The HSS Twist Drill Bit Ground is manufactured to DIN 338. The drill bit is Type N (flute angle) with a 135-degree tip and a diameter tolerance of h8.  Features: Precision-ground bit made of HSS enables fast results No need to pre-punch or pilot drill up to 10 mm-diameter HSS Twist Drill Bit offers solid drilling for standard usage with metal 135-degree self-centring split-point tip combines active cutting and perfect centring without wandering Specification: Pack Qty: 5 Diameter: 4.0mm Total length: 119mm Working length: 78mm