Point Cut of Twsit Drill Bits
Helical Point Normal Ground [...]
Cutting Portion,Web thickness,Margin width of Twsit Drill
Cutting Portion σ=Point angle Ψ=Chisel egde Web thickness K Test values: the web thickness according to Fig.1 shall not be less than the minimum value K(min) indicated in Fig.2. Test point: at the point of the drill Test equipment: slide gauge with measuring points Margin width b Test values: the land width as in Fig.3 shall lie within the limitting values indicated in Fig.4. Teseing equipments: slide gauge
Dimensions Technical data of Twist Drill Bits
Drill Diameter The values indicated in the relevant dimensional standards apply in respect of the diameter of Twist Drills Test Point : on the leads at the corners（see Fig.1 ) Test equipment: micrometer Tapering of Diameter The diameter of twist drills usually reduces from the drill tip towards the shank in the area of the flute Test values : the taper on diameter amoutns to 0.02 to 0.08mm over a length of 100mm Test point: at the outside diameter on the land Test equipment : micrometer and [...]