Description: This drill set is made of high speed steel material, which has high hardness and long service life. Used for producing center holds in components or work pieces with require machining between centers. Features: Each drill has a double end and is ground with a standard 60 degree angle. 1/2/2.5/5mm center drill bit for your different needs. Make a conical hole for a lathe center in order to make a starting point for a standard twist drill, designed to prevent the twist drill from walking. Made of high speed steel material, which has high hardness and long service life. Surface nitride treatment, easy to clean. Specification: Material: HSS Surface treatment: nitride treatment Type: 1/2/2.5/5mm Size(Approx.): 35*1mm / 1.3*0.03inch 40*2mm / 1.57*0.07inch 45*2.5mm / 1.7*0.09inch 60*5mm / 2.3*0.19inch Weight: 46g Quantity: 4pc Package Included: 4 x Centering Drill Bits Note: Due to the light and screen difference, the item's color may be slightly different from the pictures. Please allow 1-3mm differences due to manual measurement. Thank you for your kindly understanding. 1、Each drill has a double end and is ground with a standard 60 degree angle. 2、1/2/2.5/5mm center drill bit for your different needs. 3、Make a conical hole for a lathe center in order to make a starting point for a standard twist drill, designed to prevent the twist drill from walking. 4、Made of high speed steel material, which has high hardness and long service life. 5、Surface nitride treatment, easy to clean.