DART 3 Flute HSS Countersink - 6 piece Set Dart Log in for pricing Precision engineered, high speed ground steel countersink bits. This set contains, 6.3, 8.3, 10.4, 12.4, 16.5, 20.5mm bits. Three 90 degree cutting edges for rapid swarf clearance. Manufactured to... DCS3-SET6 Log in for pricing Stock: Qty in Cart: 0 Price: Log in for pricing Subtotal: