National Machine Takes a Plunge

On a torque tube operation, milling out multiple radiuses with a standard OSG 3/8-in. tin-coated 4- flute carbide endmill was not working for National Machine. The operation was too long and the tool life poor on material 4140. This operation made multiple arc or helical moves at half diameter until correct radius was achieved, then it would duplicate that process at full depth, or 2x diameter.

An Iscar product specialist was called in to evaluate the process of this complex part. The solution was the Iscar Multi-Master MM HT 100CO8RO.5-2-2T06 toroidal insert. This tool was able to plunge the material out in one thrust. Iscar's Multi-Master is a new family of tools with shanks and unique interchangeable heads for a variety of milling applications including ball nose, straight shoulder and slitting and slotting. Indexing is fast and convenient due to the threaded connection. Since the tool is not removed from the machine, there is no setup time for head replacement. Multi-Master is a high-tech substitute for HSS and solid carbide milling cutters.

Excellent repeatability is now possible and re-sharpening of tools is no longer needed. Multi-Master milling heads feature advanced pressed geometries with sharp-ground cutting edges. End milling heads are available in Iscar grade IC908 (a submicron substrate with a PVD TiAlN coating), enabling high-speed machining with toughness and wear resistance. Slitting and slotting heads are available in very tough grades designated IC328 and IC528. They are designed for a multitude of deep cavity machining applications. This Multi-Master system is essential for die and mold production, providing long shank options and a high degree of machining efficiency.

Multi-Master proved itself again. By plunging instead of side milling, valuable time was saved. Additionally, resetting the tool went from a 15 minute process to less than one minute. Taking 30 minutes out of the cycle time resulted in a $5,000 (73%) savings on the balance of the parts needing to be manufactured. Surface quality went from good to excellent, and machining went from noisy to quiet. Parts per cutting edge went from three to 15 (The operator requested the change to avoid breakage, but the tool could have exceeded the 15 parts).