Smithy GN1300 - Manual (Page 105)

Cutting Speed and Feeds for
High Speed Steel Tools
The energy expended at the lathe's cutting point converts largely into heat, and because
the energy expended is great, the heat is intense. Before today's HSS, carbide, and
ceramic tool, this heat created a serious machining problem. Machining could be done
only under a steady flow of coolant, which kept the tool from heating to its annealing
point, softening, and breaking down.
With HSS, you can cut dry on cast iron or non-ferrous metals unless a small lathe is
running at extremely high speed on continuous, heavy-duty production work. Because
steel expands when heated, it is a good idea, especially when working on long shafts, to
check the tightness of the lathe centers frequently and make sure workpiece expansion
does not cause the centers to bind.
Cutting Speeds and Feeds for High Speed Steel Tools
! NOTICE !
The data table provides exact speeds (RPM). It
does not take machine speed limitations into
account. Determine the desired rate of speed and
find the closest speed available on your machine.
Low-Carbon
Steel
High-
Carbon
Steel
Annealed
Alloy Steel
Normalized
Aluminum
Alloys
Cast Iron Bronze
Speed (sfm)
Roughing
Finishing
90
120
50
65
45
60
200
300
70
80
100
130
Feed (ipr)
Roughing
Finishing
0.010-0.202
0.003-0.005
1.101-0.020
0.003-0.005
0.010-0.020
0.003-0.005
0.015-0.030
0.005-0.010
0.010-0.020
0.003-0.010
0.010-0.020
0.003-0.10
Appendix A: Machining Reference Guide
A-3 Or Visit www.smithy.com