With a new level of built-in asymmetry, ISCAR EC-H CHATTERFREE solid carbide endmills bring a new level of speed and process security to slotting and shoulder milling of ferrous metals. On alloy and stainless steel, users report 20-25% longer tool life than with ordinary variable-pitch endmills.
Familiar variable-pitch flutes have proven out for years for their vibration-dampening characteristics in solid carbide endmills. Now ISCAR has gone one step better by varying the helixes as well. Two flutes have a 35o helix angle and the other two ascend at 37o.
ISCAR’s theory is that the more asymmetry they design into a solid carbide tool, the greater its resistance to harmonic vibration and chatter.
The variable helix adds one extra dampening influence against harmonic vibrations, a principal cause of tool fracture in hard but brittle solid carbide endmills. By the same mechanism it also further minimizes chatter marks in the workpiece.
EC-H CHATTERFREE endmills are available in the diameter range of 6-25 mm, with either Weldon (relieved) or cylindrical (straight) shanks. All have corner radii and are made of IC900, the most versatile PVD coated grade available today.
Besides defeating vibration, ISCAR EC-H CHATTERFREE endmills feature a free- cutting edge geometry that improves chip evacuation and reduces cutting forces, suiting them ideally for low power machines with ISO 40 or BT40 adaptations. With such improved control over vibration and cutting forces, they can safely be used on slots up to 2.5 x D in alloy and stainless steel.
Four-flute EC- H CHATTERFREE endmills come in three types: standard lengths with cylindrical shanks, standard lengths with relieved shanks and extra long 4 x D mills with cylindrical shanks.
Two early applications underscore the added performance of the variable-helix/variable-flute endmill vs. standard variable-flute tool. In rough shoulder milling of an austenitic stainless steel workpiece, the material removal rate improved to 20.05 cm3/min., from 9.17 with the tool change, and tool life improved to 45 pieces vs. 30, before flank wear necessitated replacement. The main improvement with the EC-H cutter stemmed from doubling the depth of cut, which would have snapped off the competing tool. Also, in the case of a rough slotting operation with X6CrNiMoTi17-12-2, the EC-H CHATTERFREE endmill lasted through 60 pieces under identical conditions that had snapped off the competing endmill at 45 pieces.
