To finely machine bores with large diameters in a defined tolerance range, users are often faced with the option of reaming or fine boring. On one hand, multi-cutting edged reaming tools are extremely fast and are less sensitive to an interrupted cut. However, the reconditioning of reamers with fixed inserts is a complex process.
To simplify this process by reducing the quantities of tools in circulation and the subsequent logistics and even tool-setting effort, MAPAL has developed the high-performance reaming tool HPR400. By incorporating high-accuracy insert seats, customers can replace the inserts of the HPR400 instantly using a torque wrench. Incorrect insert mounting is eliminated, as only one mounting position is possible and the inserts can be fitted in any pocket.
As a result there is no setting effort and there is no need to send tools for time consuming or expensive reconditioning. With the new HPR400, customers only need to have the suitable HPR400 inserts from MAPAL in stock. The quantity of tools required will also be at a minimum, as tool bodies do not need to be reconditioned. With minimal effort and a low number of tools in circulation, customers can achieve extremely accurate bores with the MAPAL HPR400.
The principle of the HPR400 system can be combined with other processes and therefore be designed as a combination tool. The reaming tool has an internal coolant supply that distributes the cooling lubricant directly to the cutting edge. Furthermore, the design behind the HPR400 incorporates an unequal spacing of the insert seats and this ensures a quiet and smooth cutting process.
Inserts adapted to workpiece material and machining
The HPR400 is available from 50 to 315mm diameter with either a HSK configuration or MAPAL’s own module adaptor. The HPR400 can be applied to almost any workpiece material as the inserts are available in with variety of grades and geometries that can be adapted accordingly. MAPAL offers indexable carbide inserts with or without CVD coating or alternately there is a Cermet and tipped line that is offered with PCD or PcBN.
For unparalleled reliability when machining cast iron, MAPAL has developed the extremely wear-resistant HC419 insert grade with a CVD coating. This material has proven itself with high cutting data and exceptional tool life whilst the CVD coating enables a very broad range of alloys to be machined. This is all the more important, as the further development of cast materials for thermal stability and lightweight construction is continuous. The HPR400 with the HC419 grade is already being successfully implemented by numerous automotive manufacturers producing everything from brake callipers and swivel bearings through to gearbox housings.
One automotive customer is applying the HPR400 to the machining of the main bore in a differential housing. Running on a GJS400 workpiece material with a too diameter of 150mm using eight inserts, the HPR400 is obtaining a tolerance level of IT7 with a high-quality surface finish. These results arrive from running the HPR400 at a cutting speed of 160m/min with a feed of 1.6mm to get an average roughness of Ra= 1.35µm. For further information on how your precision holemaking can benefit from the HPR400, contact MAPAL UK.
