WNN15 grade from Walter is an extremely reliable, low-adhesion grade that’s now also included in the company’s indexable insert drills. The drills that accept indexable inserts made of grade WNN15 include D4120, D3120, and B3212.DF. to B3214.DF in insert versions P4840, P2840, and LCGX.

The grade is primarily designed for drilling wrought or cast aluminum alloys (ISO N workpiece group). Applications for these alloys are mainly found in the aerospace and automotive industries, as well as in general mechanical engineering.

The drilling grade WNN15 features a hard substrate, which ensures outstandingly high cutting-edge strength and sharpness on indexable inserts. In addition to exceptional process reliability, the inserts offer a high level of wear resistance to provide long tool life even at extremely high cutting speeds. An increase in tool life of up to 200% can be achieved compared to conventional drilling grades, depending on the application. These capabilities make drilling with the grade WNN15 indexable inserts more cost-effective than comparable PCD tools.

A physical vapor deposition (PVD) coating is applied to the grade WNN15 inserts using the high-power impulse magnetron sputtering (HiPIMS) process to create an incredibly smooth, dense surface. The rake faces are also polished. As a result, chip evacuation is smooth and built-up edge (BUE) is avoided on the tool/workpiece interface. The inserts are also very cost efficient due to 4 indexes per insert.

Additionally, Walter has introduced uncoated polished grade WN15 with a fine-grained substrate also suitable for aluminum machining. This uncoated grade WN15 complements the coated PVD grade WNN15 described above but serves as an ‘economical alternative’ with approximately 30% lower cost/cutting edge. The drills that accept WN15 grade inserts include D4120, D3120, and B3212.DF. to B3214.DF in insert versions P4840, P2840 and LCGX.