Technical Information

Technical Information
Technical Information
KM4X Spindle Connection
Why Bending Load Capacity Is Important
When machining tough materials like titanium, cutting speeds are relatively low
due to thermal effects on cutting tools. Over the years, machine tool builders
responded to this issue by improving stiffness and damping on spindles and
machine structures. Spindles have been designed with abundant torque
at low rotational speeds. Nevertheless, the spindle connection has remained
the weak link in the system.
The spindle connection must provide torque and bending load capacity
compatible with the machine tool specifications and the requirements for higher
productivity. It becomes obvious that in end-milling applications where the
projection lengths are typically greater, the limiting factor is the bending load
capacity of the spindle interface.
The lines on the chart to the right represent the load capacity of HSK, PSC,
and KM4X. The shaded areas represent the typical requirements for heavy-duty
applications in various machining processes. KM4X is the only system that can
deliver the torque and bending capacity required for achieving high-performance
machining. Some systems may be able to transmit a considerable amounts of
torque, but the cutting forces also generate bending moments that exceed the
interface’s limits before torque limits are exceeded.
deflection (m) @ 150mm
M10 www.kennametal.com
torque
Drilling
Face Milling
SK-F (7/24 Taper with Face Contact)
SK (7/24 Taper)
HSK
bending moment
Turning
End Milling
0.20
0.18
0.16
0.14
0.12
0.10
0.08
0.06
0.04
0.02
0.00
0 600 1200 1800 2400 3000 3600 4200 4800 5400 6000
bending moment (Nm)
7/24 Taper — Size 50
KM4X100
7/24 Taper — Size 50
with Face Contact
HSK125A
7/24 Taper — Size 60
KM4X125
PSC
TS (KM)
IMPORTANT
Information shown on the following charts was developed exclusively for use with KM tooling in static conditions. Do not use for any other tooling
system because the results will not apply. To account for cutting force fluctuations in dynamic conditions, a reduction of 20–30% should be applied
to the loads shown in charts.
Chart shows load-deflection comparison of steep taper with and without face contact — HSK and KM4X.
HSK100A
KM4X
Deep Boring
150mm
F
deflection