Dormer Tools has introduced a range of taps for material specific applications branded “Shark Line”.
Designed to obtain superior performance, all Shark taps feature a coloured ring that signifies the specific material type it is suited to.
The programme encompasses spiral point taps for through-hole applications, spiral flute taps for threading blind holes and, in the case of white ring taps for cast iron, straight flute taps for both through or blind holes.
So, is there a need for material specific taps? Dormer’s Marketing Manager, Simon Winstanley, answers the question: “Simply because of the multitude of forces exerted on the cutting edges, producing threads with taps is one of the most difficult machining processes a solid round tool can perform.
“Working with a general cutting geometry in materials that have a low resilience will have the effect that the actual diameter of cut thread will be too large. In materials that have a high resilience the threads of the tap will become enclosed by the material with increased risk of breakage. Entering the workpiece material with rake and relief angles that are specifically suited for that range of materials is essential for producing the optimum thread.”
Shark Line taps are manufactured from a HSS-E-PM substrate specifically developed for taps to give the additional toughness required, consistently stable properties and a superior grind-ability compared to conventional high-speed steels. These improved characteristics mean the taps have a more predictable and assured life.
Advanced geometry ensures the production of excellent threads at both high and low cutting speeds. Furthermore it prevents unnecessary built up edge and wear on the cutting edges to ensure longer tool life. In addition it provides a superior thread surface finish. The different geometries for blind and through holes have been optimised to ensure process security.
Extra fine surfaces due to improved grinding technology enables the advanced surface coating to have a smoother finish. This reduces the risk of chipping, increases tool life and allows higher cutting speeds. And, the application specific cutting edge treatment ensures optimal performance.
Yellow Shark is designed for threading low alloy steels, and is available with an electroplated Hard Chrome finish up to 5 micron thick to prevent edge build-up in materials that are prone to sticking to the cutting edges. The flute geometry has been designed to prevent swarf nesting, reducing the risk of re-cutting swarf on reversal.
Red Shark is designed for high performance thread production in alloy steels and is available in Bright finish or with TiAlN-Top coating for increased protection against abrasive wear and erosion. When combined with edge preparation it guarantees exceptional performance in alloy steels. The spiral flute version features back taper design to diminish chipping on the last few threads of the tap and reduce the torque required to reverse the tool.
The production of threads in a wide range of stainless steels is achieved with Blue Shark. Available with Steam Temper or Super-B (a hard lube coating that prevents chips adhering to the flutes) coatings with specific edge preparation these taps provide extended tool life in even the most difficult stainless steels.
The White Shark has been developed specifically for cast iron and other short chipping materials. Available with the Steam Temper or TiAlN coating options it features a straight flute design which enables production of both through and blind holes.
Green Shark is the final material specific thread cutting option currently offered by Dormer, and it has been developed for non-ferrous materials with a Bright or TiAlN-Top finish to provide exceptional cutting service life in aluminium and its alloys, brass and copper.