Page 175 - Demo

173PRE-THREAD DRILLING WITH CHAMFERING Recommendation for Better Stability2 It is recommended to use the same cutting conditions for both chamfering and drilling operations.3 For optimal chip formation and to prolong chamfering insert edge life, it is recommended to use external coolant directed to the chamfering inserts, in addition to the CHAM-DRILL%u2019s internal coolant.4 The UNI-CHAM-DRILL projection should not be adjusted beyond the peripheral clearance guide surfaces on the UNI-CHAM-DRILL flutes.5 The chamfering insert screws should not be tightened before the initial tightening of the CHAM-RING side clamping screw. Incorrect drill orientation can lead to breakage of the chamfering inserts.6 In case vibrations occur during the chamfering operation, it is recommended to change the adapter to a more rigid one. If the vibrations continue, reduce the speed and increase the feed (in the chamfering operation only). This will reduce vibration without reducing productivity.7 In case vibrations occur during the chamfering operation in a through hole application, it is recommended to reduce the speed.8 The recommended chamfer size should not be exceeded.9 Chamfering inserts should not be used for counterboring.10 When machining the maximal chamfer size, the recommended cutting parameters must be reduced by 20%.11 The chamfer size gets smaller proportionally when a larger CHAM-DRILLhead is used. The maximal chamfer size is obtained when using the smallest CHAM-DRILL head.