1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 0.0087 0.0174 0.0261 0.0349 0.0436 0.0524 0.0611 0.0699 0.0787 0.0874 0.0963 0.1051 0.1139 0.1228 0.1316 0.1405 0.1494 0.1583 0.1673 0.1763 0.1853 0.1943 0.2034 0.2125 0.2216 0.2308 0.2400 0.2493 0.2586 0.2679 0.2773 0.2867 0.2962 0.3057 0.3153 0.3249 0.3346 0.3443 0.3541 0.3639 0.3738 0.3838 0.3939 0.4040 0.4142 0.4244 0.4348 0.4452 0.4557 0.4663 0.4769 0.4877 0.4985 0.5095 0.5205 0.5317 0.5429 0.5543 0.5657 0.5773 0.5890 0.6008 0.6128 0.6248 0.6370 0.6494 0.6618 0.6745 0.6872 0.7002 0.7132 0.7265 0.7399 0.7535 0.7673 0.7812 0.7954 0.8097 0.8243 0.8391 0.8540 0.8692 0.8847 0.9004 0.9163 0.9324 0.9489 0.9656 0.9827 1.000 1.017 1.035 1.053 1.072 1.091 1.110 1.130 1.150 1.170 1.191 1.213 1.234 1.257 1.279 1.303 1.327 1.351 1.376 1.401 1.428 1.455 1.482 1.510 1.539 1.569 1.600 1.631 1.664 1.697 1.732 1.767 1.804 1.841 1.880 1.921 1.962 2.005 2.050 2.096 2.144 2.194 2.246 2.299 2.355 2.414 2.475 2.538 2.605 2.674 2.747 2.823 2.904 2.988 3.077 114.59 3.171 3.270 3.375 3.487 3.605 3.732 3.866 4.010 4.165 4.331 4.510 4.704 4.915 5.144 5.399 5.671 5.975 6.313 6.691 7.115 7.595 8.144 8.776 9.514 10.38 11.43 12.70 14.30 16.35 19.08 22.90 26.63 38.18 57.29 Inf. Degree Degree Degree Degree Degree K K K K K Figure 4-122.  K-factor.  A minimum radius of bend is specified for each type of  aircraft sheet metal. The minimum bend radius is affected  by the kind of material, thickness of the material, and temper  condition of the material. Annealed sheet can be bent to a  radius approximately equal to its thickness. Stainless steel and  2024-T3 aluminum alloy require a fairly large bend radius.  To understand the process of making a sheet metal layout,  the steps for determining the layout of a sample U-channel  will be discussed.  [Figure 4-123]  When using bend  Bending a U-Channel Figure 4-123.  U-channel example. Isometric view Scale: 3:2 .04 R=.16 2.0 1.0 Left view Scale: 3:2 4-61