Table 15b. End Milling (Full Slot) Speed Adjustment Factors for Feed, Depth of Cut, and Lead Angle Cutting Speed, V = V opt 3 F f 3 F d
Ratio of the two cutting speeds
Depth of Cut and Lead Angle
Ratio of
( average / optimum ) given in the tables
V avg / V opt 1.00 1.25 1.50 2.00 2.50 3.00 4.00 0 °
1 in (25.4 mm)
0.4 in (10.2 mm)
0.2 in (5.1 mm)
0.1 in (2.4 mm)
0.04 in (1.0 mm)
Chosen Feed to Optimum Feed
45 °
0 °
45 °
0 °
45 °
0 °
45 °
0 °
45 °
Feed Factor, F f
Depth of Cut and Lead Angle Factor, F d
1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10
1.0 1.0 1.0 1.0 1.0 1.0 1.0 0.91 1.00 1.06 1.09 1.14 1.18 1.21 1.27 0.91 1.00 1.12 1.19 1.31 1.40 1.49 1.63 0.92 1.00 1.18 1.30 1.50 1.69 1.85 2.15 0.93 1.00 1.20 1.40 1.73 2.04 2.34 2.89 0.94 1.00 1.25 1.50 2.00 2.50 3.00 4.00 0.95 1.00 1.23 1.57 2.29 3.08 3.92 5.70 0.96 1.00 1.14 1.56 2.57 3.78 5.19 8.56 0.98 1.00 0.90 1.37 2.68 4.49 6.86 17.60 1.00 1.00 0.44 0.80 2.08 4.26 8.00 20.80 1.05
1.36 1.33 1.30 1.26 1.22 1.17 1.11 1.04 0.85 0.82
0.94 0.94 0.95 0.95 0.96 0.97 0.97 0.99 1.00 1.00
1.38 1.35 1.32 1.27 1.25 1.18 1.12 1.04 0.95 0.81
1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
0.71 0.72 0.74 0.76 0.79 0.82 0.86 0.91 0.99 1.50
1.29 1.26 1.24 1.21 1.18 1.14 1.09 1.04 0.97 0.85
1.48 1.43 1.39 1.35 1.28 1.21 1.14 1.07 0.93 0.76
1.44 1.40 1.35 1.31 1.26 1.20 1.13 1.05 0.94 0.78
1.66 1.59 1.53 1.44 1.26 1.21 1.16 1.09 0.88
0.67 For HSS (high-speed steel) tool speeds in the first speed column of Table 10 through Table 14, use Table 15a to determine appropriate feeds and depths of cut. Cutting speeds and feeds for end milling given in Table 11 through Table 14 (except those for high-speed steel in the first speed column) are based on milling a 0.20-inch deep full slot (i.e., radial depth of cut = end mill diameter) with a 1-inch diameter, 20-degree helix angle, 0-degree lead angle end mill. For other depths of cut (axial), lead angles, or feed, use the two feed/speed pairs from the tables and calculate the ratio of desired (new) feed to optimum feed (largest of the two feeds are given in the tables), and the ratio of the two cutting speeds ( V avg / V opt ). Find the feed factor F f at the intersection of the feed ratio row and the speed ratio column in the left half of the Table. The depth of cut factor F d is found in the same row as the feed factor, in the right half of the table under the column corresponding to the depth of cut and lead angle. The adjusted cutting speed can be calculated from V = V opt 3 F f 3 F d , where V opt is the smaller ( optimum ) of the two speeds from the speed table (from the left side of the column containing the two feed/speed pairs). See the text for examples. If the radial depth of cut is less than the cutter diameter (i.e., for cutting less than a full slot), the feed factor F f in the previous equation and the maximum feed f max must be obtained from Table 15c. The axial depth of cut factor F d can then be obtained from this table using f max in place of the optimum feed in the feed ratio. Also see the footnote to Table 15c.
Made with FlippingBook - Share PDF online