Although conventional carbide twist drills are capable of producing finely divided chips, when machining steel materials such as carbon steel, alloy steel and stainless steel, elongation of chips can easily occur. The unstable chip shape interferes with chip evacuation, which is especially problematic in deep- hole drilling, and may lead to sudden tool breakage.
The ADO’s newly developed R gash geometry expands the chip room at the centre of the tool where chips are di cult to be discharged. With the optimised R shape to guide the direction of chip flow, chips can be evacuated smoothly. Moreover, with this new feature, the curling of chips is controlled, and the consistency of chip shape has significantly improved to allow superior chip separation versus the conventional design. In addition, the cutting force (thrust resistance) is reduced by approximately 30 per cent compared to the conventional design, thereby enabling the suppression of machining vibration in high-feed machining and improves straightness during drilling.
The second key feature of the ADO long drill is its new flute specification that enables smooth evacuation of the compact chips created by the R gash geometry, while maintaining high tool rigidity of the long tool body necessary for 40xD and 50xD applications. Chip evacuation capability has been greatly amplified by expanding the width of the flute, which functions as chip room. A 25-degree helical flute geometry is applied to enhance rigidity without interfering chip evacuation capability.
Last but not least, just as important as the previous two key features is the adoption of OSG’s original EgiAs coating for high durability. The EgiAs coating is consist of overlapping nano-periodical layers and wear-resistance layers, engineered to suppress the propagation of cracks that are likely to occur during drilling. The wear-resistance layer is composed of multiple hard layers while the nano-periodical is a combination of hard and soft layers. With a mixture of hard and soft layers, internal stress can be relieved, allowing the EgiAs coating to achieve both high wear resistance and extreme toughness to ensure stable and consistent tool life under aggressive cutting conditions.
The most notable advantages of the ADO long drill are its consistent chip separation ability, low cutting resistance, and capability to achieve a fine balance between tool rigidity and trouble-free chip evacuation regardless of the long cutting depth to allow stable and efficiency processing.
For further details contact Somta Tools on TEL: 011 390 8700 or visit www.somta.co.za