Page 190 - Demo

188 ISCAR SPOT DRILLING AND CHAMFERING %u00bd%u0009Spot Drilling vs Pre-DrillingIn some cases, the most common way to create a correct drill center location at the start of a plunge initiation is by spot drilling or pre-drilling. The dilemma often arises, which of these methods is preferable? Whether to create a pre-drilled hole using a short drill bit with a diameter similar to the required diameter or to create a dimple using a spot drill? The answer is not always clear and depends on various parameters such as: availability of the tool in stock, workpiece form, workpiece material, requested hole requirements, machine center accuracy, operation stability, etc. Therefore, to select the correct method, it is necessary to consider each specific case separately.Preparing OperationSpot Drilling Pre-DrillingFinal Operation