For HSS (high-speed steel) tools in the first speed column only, use Table 15a for recommended feed in inches per tooth and depth of cut. End Milling: Table data for end milling are based on a 3-tooth, 20-degree helix angle tool with a diameter of 1.0 inch, an axial depth of cut of 0.2 inch, and a radial depth of cut of 1 inch (full slot). Use Table 15b to adjust speeds for other feeds and axial depths of cut, and Table 15c to adjust speeds if the radial depth of cut is less than the tool diameter. Speeds are valid for all tool diameters. Face Milling: Table data for face milling are based on a 10-tooth, 8-inch diameter face mill, operating with a 15-degree lead angle, 3 ∕ 64 -inch nose radius, axial depth of cut = 0.1 inch, and radial depth (width) of cut = 6 inches (i.e., width of cut to cutter diameter ratio = 3 ∕ 4 ). These speeds are valid if the cutter axis is above or close to the center line of the workpiece (eccentricity is small). Under these conditions, use Table 15d to adjust speeds for other feeds and axial and radial depths of cut. For larger eccentricity (i.e., when the cutter axis to workpiece center line offset is one half the cutter diameter or more), use the end and side milling adjustment factors (Table 15b and Table 15c) instead of the face milling factors. Slit and Slot Milling: Table data for slit milling are based on an 8-tooth, 10-degree helix angle tool with a cutter width of 0.4 inch, diameter D of 4.0 inches, and a depth of cut of 0.6 inch. Speeds are valid for all tool diameters and widths. See the examples in the text for adjustments to the given speeds for other feeds and depths of cut. Tool life for all tabulated values is approximately 45 minutes; use Table 15e to adjust tool life from 15 to 180 minutes. The combined feed/speed data in this table are based on tool grades (identified in Table 16) as follows: uncoated carbide = 20, † = 15; coated carbide = 10; CBN = 1. Table 13. Cutting Speeds and Feeds for Milling Stainless Steels
End Milling
Face Milling
Slit Milling
Uncoated Carbide
Coated Carbide
Coated Carbide
Uncoated Carbide
Coated Carbide
HSS
HSS
Brinell Hardness Number 135-185 135-185 185-240 275-325 375-425 135-185
f = feed (0.001 in/tooth), s = speed (ft/min) Metric Units: f 3 25.4 = mm/rev, s 3 0.3048 = m/min Opt. Avg. Opt. Avg. Opt. Avg. Opt. Avg. Opt. Avg. Opt. Avg.
Speed (fpm)
Material
f s
Free-machining stainless steels (Ferritic): 430F, 430FSe (Austenitic): 203EZ, 303, 303Se, 303MA, 303Pb, 303Cu, 303 Plus X (Martensitic): 416, 416Se, 416 Plus X, 420F, 420FSe, 440F, 440FSe Stainless steels (Ferritic): 405, 409, 429, 430, 434, 436, 442, 446, 502 (Austenitic): 201, 202, 301, 302, 304, 304L, 305, 308, 321, 347, 348 (Austenitic): 302B, 309, 309S, 310, 310S, 314, 316, 316L, 317, 330
7 30 7 20
4 80 4 55
7 305 7 210
4 780 4 585
7 420
4 1240
39 210
20 385
39 120
20 345 20 240
39 155
20 475
110 100 80 110 100 60 30
{ 135-185 225-275
39 75
f s
{
f s
7 30
4 80
7 305
4 780
7 420
4 1240
39 210
20 385
39 120
20 345
39 155
20 475
90 75 65 70 95 85 55 35
{ 135-185 225-275
f s
7 20
4 55
7 210
4 585
39 75
20 240
135-185 135-175 175-225 275-325 375-425
(Martensitic): 403, 410, 420, 501
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