High-Performance Solid Carbide End Mills
Trochoidal Milling
Helix Angle and Chip Thickness
The chip thickness (h) depends on the helix angle of the cutting edge. If the feed fz is constant, the chip thickness
gets thinner as helix angle rises. That means with more helix angle, the chip gets thinner — or you can rise feed rate
to increase productivity and load to the cutting edge.
Calculation of Chip Thickness
The chip thickness (h) is not constant, but defi nes the load of the cutting edge. By reducing the load on the cutting edge,
machining at higher speeds is possible through the machining parameters. For easier calculation, use an average chip
thickness hm. When calculating machining data this way cutting data may be compromised because the workpiece is
often a different shape.
fz
fz
fz
B
ap
b
r
fz
qs/2
qs/2
hm
h
hm =
ae
360º
•
• fz • sin r
/ • qs
D
=
average chip thickness
qs [°] = engagement angle
ae [mm] = width of engagement
D1 [mm] = outer diameter tool
fz [mm] = feed per tooth
r [°] = lead angle
h [°] = helix angle *
* Solid End Mills: r = 90°-h
NOTE: It makes no difference if the tool is solid or an indexable milling tool.
widia.com
O209
hm [mm]