Plunge milling ingenuity from WNT

WNT’s latest solid carbide milling development, the Monstermill PCR UNI enables precise, process-secure, ramping/plunge milling at high angles or with extreme chip volumes during full slot milling, providing a new milling solution thanks to its innovative geometry, four flute design and patented centring tip. The design delivers powerful and extremely quiet milling across a range of materials including steel, stainless steels and cast iron.

With the MonsterMill PCR UNI, WNT brings an immensely powerful tool to the table that will enhance machining capability, allowing customers to experience a new world of milling. Not only does the PCR cutter excel at roughing and finishing, it is also a master of vertical plunging. The MonsterMill PCR UNI’s four cutting edges give it a significant advantage over conventional plunge milling cutters with only three, as it can achieve feed rates that are up to a third higher. For ramping/plunging, slotting and profiling operations feed/tooth rates of up to 0.137 mm/rev are also possible.

Despite the high cutting speeds afforded by the PCR UNI, the cutters also achieve high process security thanks to the special core geometry that has been designed to break chips and prevent spiral chips forming during plunging and drilling. Thanks to the reliable swarf removal via the flutes, therefore the elimination of chip jams a more secure machining process is achieved. "We've compared the MonsterMill PCR UNI with two competitors. One of the plunge milling cutters did not break the chip at all and long continuous chips were formed. With the other milling cutter, drilling was only possible to a limited extent and a large built-up edge formed," says WNT Product Manager Daniel Rommel. "With the MonsterMill PCR UNI we witnessed excellent chip breakage and process-secure chip removal at higher feed rates."

The cutter design also creates a quieter cutting process, thanks in part to the irregular flute pitch and helix angle on the milling cutter. This has the effect of preventing the tool from oscillating and starting to vibrate, even when high ramping angles of up to 45° are being used, without reducing feed rates. Another feature of the PCR UNI cutter is its ability to ensuring a stable process and maximum precision during angled ramping up to 90°. This is achieved thanks to the patented 142° centring tip in the centre of the end cutting edge, it also means that rapid centring is possible without having to perform helical milling in advance. Daniel Rommel explains: “If users need to make a hole on a sloping surface, they previously had to mill down in a helix to 1xD so that the drill is then guided laterally. Thanks to the centring pin of the PCR UNI, this process has become a thing of the past.” There are also advantages when helical milling due to Monstermill PCR UNI’s high ramping angle – up to 25° for helical drilling – "With the conventional method, it took 25 minutes to drill 100 holes (10 mm diameter), but with the MonsterMill we managed it in only 8 minutes and therefore trebled the level of performance."

In developing MonsterMill PCR UNI WNT has produced a true all-round cutter that exhibits high chip removal rates during roughing with four cutting edges and achieves and excellent surface finishes as a finishing cutter. Users benefit from its very quiet running, stable and precise machining processes, and the ability to achieve angled plunging, rapid centring owing to the patented centring tip and vibration-free ramping up to a ramping angle of 45° at elevated cutting data.

Anyone wishing to test the qualities of the new MonsterMill PCR UNI can call the free service line on 0800 073 2073 to speak with the machining specialists at WNT or, arrange a face-to-face meeting with their local WNT Technical Sales Engineer.

Further information, including a product video on the MonsterMill PCR UNI, can be found at