Helical milling is a hole-making machining process in which the cutter proceeds a helical path while rotating around its own axis, used to produce helical parts like helical gears, spiral flute milling cutters, twist drills, and helical cam grooves. SPMT for helical milling. S - Square shape of turning insert. P - Insert with clearance under main cutting edge (11°). M - Tolerances and dimensions of carbide turning insert. T - Hole through insert and single sided chip breaker.1.How to choose the grade? Grades of inserts are selected primarily based on: The ISO P, M, K, N, S, and H components indicate the method (finishing, medium, roughing) Manufacturing conditions (good, average, difficult) 2.How to choose an insert shape? Selecting the smallest possible nose angle is recommended to provide insert strength and reliability. The margin for error has to be weighed against the variety of cuts made. It requires more machine power and is more likely to vibrate more strongly when the nose angle is large. In addition to having a smaller nose angle, a minor cutting edge engagement can also make it more heat-sensitive as both of these things are weaker and more sensitive to heat. 3.How to choose a size? Adapting the insert size to the application’s requirements, as well as the space available for the cutting tool, should be considered. The stability increases when the insert has a larger size. If you are going to be doing heavy machining, then the insert size should usually be over I.C. 25 mm (1 inch). In many cases, the size of a finished product can be reduced when it is finished.
Type
Ap
(mm)
Fn
(mm/rev)
Grade
CVD
PVD
VK3020
VK3040
VK1025
VK1325
VK1525
VK1328
VR1010
VR1520
VR1525
VR1028
VR1330
SPMT120408-PM
1.00-
6.00
0.06-
0.15
•
•
O
O
SPMT120408-KM
1.00-
6.00
0.06-
0.15
•
•
O
O
• : Recommended Grade O: Optional Grade
Length
Size(mm)
r
L
IC
S
d
12
0.8
12.7
12.7
4.76
5.5
The type of carbide grade and the coating on inserts are originally intended for steel, stainless steel and cast iron. But it also performs when milling other alloys.
The type of carbide grade and the coating on inserts are originally intended for steel, stainless steel and cast iron. But it also performs when milling other alloys.
