In addition, the new range boasts detachable head, allowing heads to be selected to suit the machine type, power available and the material being processed, with the latter now seeing structural steel and single layer laminates within the tools range of applications.
Furthermore, this latest version, says the company, brings new orders of flexibility and tool inventory reduction by enabling up to five sizes of drill head to be used with a single drill body. Drill head inserts can also be reground.
The complete Multi-Drill SMD programme covers the SMDH replaceable head type drill holder, the MTL Type drill head for high efficiency drilling of general steels and the MEL version for soft steel, grey cast iron, exotic metals and low rigidity set-ups, plus the MB for structural steel and single layer laminates.
This new Sumitomo drill programme can achieve a level of hole tolerance normally only met by an additional reaming process, with the added bonus of maintaining improved hole consistency and increased in-cut life.
Short series (3xD), long series (5xD), deep hole series (8xD) and ultra-deep hole series (12.1xD) allow effective drilling depths up to 300 mm.
Other features of the Multi-Drill SMD range are reduced tool vibration and noise generated under cutting conditions, while optimised heat dissipation is achieved via precisely positioned through- the-tool coolant holes. The high rigidity clamping system ensures edge security and repeatable hole size for the exchangeable drilling heads that are bolted to the body against fixed precision-ground radial serrations.
There are two variants of drill head, one with ultra-hard PVD (MTL ACX70) coating and another with smooth PVD coating (MEL ACX80) and which has improved peeling and chipping resistance. MTL ACX70 is for general-purpose drilling applications, while MEL ACX80 will provide higher performance on lower powered machine spindles, as thrust required is some 25% lower, making this variant of the drill ideal for stainless steel or more difficult cutting conditions.
For the SMDT-MTL drill head type, cutting data for general carbon steel are: cutting speeds between 80 and 130 m/min, feed rates of 0.15 to 0.35 mm/rev – for hardened steel (HRC45): 50 and 90 m/min, feed rates of 0.1 to 0.25 mm/rev – for nodular cast iron: 70 to 110 m/min, feed rates between 0.15 to 0.4 mm/rev.
Cutting data for SMDT-MEL are, for soft steel: cutting speeds between 80 and 130 m/min, feed rates between 0.15 and 0.4 mm/rev - for stainless steel and superalloys: cutting speeds of 50 and 90 m/min, feed rates between 0.1 to 0.25 mm/rev - and for grey cast iron: 50 to 100 m/min with 0.2 to 0.45 mm/rev feed.
