重量ポンドをニュートンに換算する方法
重量ポンドの値に4.4482を掛けます。難しいのは計算ではなく読み取りです。米国の仕様書は力にも質量にも lb と書くことが多く、どちらを指すかは前後の文からしか分かりません。
N = lbf × 4.4482lbf = N ÷ 4.4482
この二つの単位が使われる場所
重量ポンドは標準重力のもとで 1 ポンドが受ける重さであり、米国の工学の単位です。ジェットエンジンの推力はこの単位で数千という値になります。 ニュートンは 1 キログラムに毎秒毎秒 1 メートルの加速度を与える力で、この名を与えられたのは 1948 年のことにすぎません。
身近な力のlbfとNの対応
| 1 lbf | 4.45 N |
| 2 lbf | 8.90 N |
| 5 lbf（ドア） | 22.24 N |
| 10 lbf | 44.48 N |
| 20 lbf | 88.96 N |
| 40 lbf（弓） | 177.93 N |
| 50 lbf | 222.41 N |
| 100 lbf | 444.82 N |
| 500 lbf | 2,224.11 N |
| 1,000 lbf | 4,448.22 N |
| 5,000 lbf | 22,241.11 N |
すべての値を表示
- 1 lbf = 4.448 N
- 2 lbf = 8.896 N
- 3 lbf = 13.345 N
- 4 lbf = 17.793 N
- 5 lbf = 22.241 N
- 6 lbf = 26.689 N
- 7 lbf = 31.138 N
- 8 lbf = 35.586 N
- 9 lbf = 40.034 N
- 10 lbf = 44.482 N
- 11 lbf = 48.93 N
- 12 lbf = 53.379 N
- 13 lbf = 57.827 N
- 14 lbf = 62.275 N
- 15 lbf = 66.723 N
- 16 lbf = 71.172 N
- 17 lbf = 75.62 N
- 18 lbf = 80.068 N
- 19 lbf = 84.516 N
- 20 lbf = 88.964 N
- 21 lbf = 93.413 N
- 22 lbf = 97.861 N
- 23 lbf = 102.309 N
- 24 lbf = 106.757 N
- 25 lbf = 111.206 N
- 26 lbf = 115.654 N
- 27 lbf = 120.102 N
- 28 lbf = 124.55 N
- 29 lbf = 128.998 N
- 30 lbf = 133.447 N
- 31 lbf = 137.895 N
- 32 lbf = 142.343 N
- 33 lbf = 146.791 N
- 34 lbf = 151.24 N
- 35 lbf = 155.688 N
- 36 lbf = 160.136 N
- 37 lbf = 164.584 N
- 38 lbf = 169.032 N
- 39 lbf = 173.481 N
- 40 lbf = 177.929 N
- 41 lbf = 182.377 N
- 42 lbf = 186.825 N
- 43 lbf = 191.274 N
- 44 lbf = 195.722 N
- 45 lbf = 200.17 N
- 46 lbf = 204.618 N
- 47 lbf = 209.066 N
- 48 lbf = 213.515 N
- 49 lbf = 217.963 N
- 50 lbf = 222.411 N
- 51 lbf = 226.859 N
- 52 lbf = 231.308 N
- 53 lbf = 235.756 N
- 54 lbf = 240.204 N
- 55 lbf = 244.652 N
- 56 lbf = 249.1 N
- 57 lbf = 253.549 N
- 58 lbf = 257.997 N
- 59 lbf = 262.445 N
- 60 lbf = 266.893 N
- 61 lbf = 271.342 N
- 62 lbf = 275.79 N
- 63 lbf = 280.238 N
- 64 lbf = 284.686 N
- 65 lbf = 289.134 N
- 66 lbf = 293.583 N
- 67 lbf = 298.031 N
- 68 lbf = 302.479 N
- 69 lbf = 306.927 N
- 70 lbf = 311.376 N
- 71 lbf = 315.824 N
- 72 lbf = 320.272 N
- 73 lbf = 324.72 N
- 74 lbf = 329.168 N
- 75 lbf = 333.617 N
- 76 lbf = 338.065 N
- 77 lbf = 342.513 N
- 78 lbf = 346.961 N
- 79 lbf = 351.41 N
- 80 lbf = 355.858 N
- 81 lbf = 360.306 N
- 82 lbf = 364.754 N
- 83 lbf = 369.202 N
- 84 lbf = 373.651 N
- 85 lbf = 378.099 N
- 86 lbf = 382.547 N
- 87 lbf = 386.995 N
- 88 lbf = 391.444 N
- 89 lbf = 395.892 N
- 90 lbf = 400.34 N
- 91 lbf = 404.788 N
- 92 lbf = 409.236 N
- 93 lbf = 413.685 N
- 94 lbf = 418.133 N
- 95 lbf = 422.581 N
- 96 lbf = 427.029 N
- 97 lbf = 431.477 N
- 98 lbf = 435.926 N
- 99 lbf = 440.374 N
- 100 lbf = 444.822 N
- 101 lbf = 449.27 N
- 102 lbf = 453.719 N
- 103 lbf = 458.167 N
- 104 lbf = 462.615 N
- 105 lbf = 467.063 N
- 106 lbf = 471.511 N
- 107 lbf = 475.96 N
- 108 lbf = 480.408 N
- 109 lbf = 484.856 N
- 110 lbf = 489.304 N
- 111 lbf = 493.753 N
- 112 lbf = 498.201 N
- 113 lbf = 502.649 N
- 114 lbf = 507.097 N
- 115 lbf = 511.545 N
- 116 lbf = 515.994 N
- 117 lbf = 520.442 N
- 118 lbf = 524.89 N
- 119 lbf = 529.338 N
- 120 lbf = 533.787 N
- 121 lbf = 538.235 N
- 122 lbf = 542.683 N
- 123 lbf = 547.131 N
- 124 lbf = 551.579 N
- 125 lbf = 556.028 N
- 126 lbf = 560.476 N
- 127 lbf = 564.924 N
- 128 lbf = 569.372 N
- 129 lbf = 573.821 N
- 130 lbf = 578.269 N
- 131 lbf = 582.717 N
- 132 lbf = 587.165 N
- 133 lbf = 591.613 N
- 134 lbf = 596.062 N
- 135 lbf = 600.51 N
- 136 lbf = 604.958 N
- 137 lbf = 609.406 N
- 138 lbf = 613.855 N
- 139 lbf = 618.303 N
- 140 lbf = 622.751 N
- 141 lbf = 627.199 N
- 142 lbf = 631.647 N
- 143 lbf = 636.096 N
- 144 lbf = 640.544 N
- 145 lbf = 644.992 N
- 146 lbf = 649.44 N
- 147 lbf = 653.889 N
- 148 lbf = 658.337 N
- 149 lbf = 662.785 N
- 150 lbf = 667.233 N
- 151 lbf = 671.681 N
- 152 lbf = 676.13 N
- 153 lbf = 680.578 N
- 154 lbf = 685.026 N
- 155 lbf = 689.474 N
- 156 lbf = 693.923 N
- 157 lbf = 698.371 N
- 158 lbf = 702.819 N
- 159 lbf = 707.267 N
- 160 lbf = 711.715 N
- 161 lbf = 716.164 N
- 162 lbf = 720.612 N
- 163 lbf = 725.06 N
- 164 lbf = 729.508 N
- 165 lbf = 733.957 N
- 166 lbf = 738.405 N
- 167 lbf = 742.853 N
- 168 lbf = 747.301 N
- 169 lbf = 751.749 N
- 170 lbf = 756.198 N
- 171 lbf = 760.646 N
- 172 lbf = 765.094 N
- 173 lbf = 769.542 N
- 174 lbf = 773.991 N
- 175 lbf = 778.439 N
- 176 lbf = 782.887 N
- 177 lbf = 787.335 N
- 178 lbf = 791.783 N
- 179 lbf = 796.232 N
- 180 lbf = 800.68 N
- 181 lbf = 805.128 N
- 182 lbf = 809.576 N
- 183 lbf = 814.025 N
- 184 lbf = 818.473 N
- 185 lbf = 822.921 N
- 186 lbf = 827.369 N
- 187 lbf = 831.817 N
- 188 lbf = 836.266 N
- 189 lbf = 840.714 N
- 190 lbf = 845.162 N
- 191 lbf = 849.61 N
- 192 lbf = 854.059 N
- 193 lbf = 858.507 N
- 194 lbf = 862.955 N
- 195 lbf = 867.403 N
- 196 lbf = 871.851 N
- 197 lbf = 876.3 N
- 198 lbf = 880.748 N
- 199 lbf = 885.196 N
- 200 lbf = 889.644 N
- 205 lbf = 911.885 N
- 210 lbf = 934.127 N
- 215 lbf = 956.368 N
- 220 lbf = 978.609 N
- 225 lbf = 1,000.85 N
- 230 lbf = 1,023.091 N
- 235 lbf = 1,045.332 N
- 240 lbf = 1,067.573 N
- 245 lbf = 1,089.814 N
- 250 lbf = 1,112.055 N
- 255 lbf = 1,134.297 N
- 260 lbf = 1,156.538 N
- 265 lbf = 1,178.779 N
- 270 lbf = 1,201.02 N
- 275 lbf = 1,223.261 N
- 280 lbf = 1,245.502 N
- 285 lbf = 1,267.743 N
- 290 lbf = 1,289.984 N
- 295 lbf = 1,312.225 N
- 300 lbf = 1,334.466 N
- 305 lbf = 1,356.708 N
- 310 lbf = 1,378.949 N
- 315 lbf = 1,401.19 N
- 320 lbf = 1,423.431 N
- 325 lbf = 1,445.672 N
- 330 lbf = 1,467.913 N
- 335 lbf = 1,490.154 N
- 340 lbf = 1,512.395 N
- 345 lbf = 1,534.636 N
- 350 lbf = 1,556.878 N
- 355 lbf = 1,579.119 N
- 360 lbf = 1,601.36 N
- 365 lbf = 1,623.601 N
- 370 lbf = 1,645.842 N
- 375 lbf = 1,668.083 N
- 380 lbf = 1,690.324 N
- 385 lbf = 1,712.565 N
- 390 lbf = 1,734.806 N
- 395 lbf = 1,757.048 N
- 400 lbf = 1,779.289 N
- 405 lbf = 1,801.53 N
- 410 lbf = 1,823.771 N
- 415 lbf = 1,846.012 N
- 420 lbf = 1,868.253 N
- 425 lbf = 1,890.494 N
- 430 lbf = 1,912.735 N
- 435 lbf = 1,934.976 N
- 440 lbf = 1,957.218 N
- 445 lbf = 1,979.459 N
- 450 lbf = 2,001.7 N
- 455 lbf = 2,023.941 N
- 460 lbf = 2,046.182 N
- 465 lbf = 2,068.423 N
- 470 lbf = 2,090.664 N
- 475 lbf = 2,112.905 N
- 480 lbf = 2,135.146 N
- 485 lbf = 2,157.387 N
- 490 lbf = 2,179.629 N
- 495 lbf = 2,201.87 N
- 500 lbf = 2,224.111 N
- 510 lbf = 2,268.593 N
- 520 lbf = 2,313.075 N
- 530 lbf = 2,357.557 N
- 540 lbf = 2,402.04 N
- 550 lbf = 2,446.522 N
- 560 lbf = 2,491.004 N
- 570 lbf = 2,535.486 N
- 580 lbf = 2,579.969 N
- 590 lbf = 2,624.451 N
- 600 lbf = 2,668.933 N
- 610 lbf = 2,713.415 N
- 620 lbf = 2,757.897 N
- 630 lbf = 2,802.38 N
- 640 lbf = 2,846.862 N
- 650 lbf = 2,891.344 N
- 660 lbf = 2,935.826 N
- 670 lbf = 2,980.308 N
- 680 lbf = 3,024.791 N
- 690 lbf = 3,069.273 N
- 700 lbf = 3,113.755 N
- 710 lbf = 3,158.237 N
- 720 lbf = 3,202.72 N
- 730 lbf = 3,247.202 N
- 740 lbf = 3,291.684 N
- 750 lbf = 3,336.166 N
- 760 lbf = 3,380.648 N
- 770 lbf = 3,425.131 N
- 780 lbf = 3,469.613 N
- 790 lbf = 3,514.095 N
- 800 lbf = 3,558.577 N
- 810 lbf = 3,603.06 N
- 820 lbf = 3,647.542 N
- 830 lbf = 3,692.024 N
- 840 lbf = 3,736.506 N
- 850 lbf = 3,780.988 N
- 860 lbf = 3,825.471 N
- 870 lbf = 3,869.953 N
- 880 lbf = 3,914.435 N
- 890 lbf = 3,958.917 N
- 900 lbf = 4,003.399 N
- 910 lbf = 4,047.882 N
- 920 lbf = 4,092.364 N
- 930 lbf = 4,136.846 N
- 940 lbf = 4,181.328 N
- 950 lbf = 4,225.811 N
- 960 lbf = 4,270.293 N
- 970 lbf = 4,314.775 N
- 980 lbf = 4,359.257 N
- 990 lbf = 4,403.739 N
- 1,000 lbf = 4,448.222 N
- 1,025 lbf = 4,559.427 N
- 1,050 lbf = 4,670.633 N
- 1,075 lbf = 4,781.838 N
- 1,100 lbf = 4,893.044 N
- 1,125 lbf = 5,004.249 N
- 1,150 lbf = 5,115.455 N
- 1,175 lbf = 5,226.66 N
- 1,200 lbf = 5,337.866 N
- 1,225 lbf = 5,449.071 N
- 1,250 lbf = 5,560.277 N
- 1,275 lbf = 5,671.483 N
- 1,300 lbf = 5,782.688 N
- 1,325 lbf = 5,893.894 N
- 1,350 lbf = 6,005.099 N
- 1,375 lbf = 6,116.305 N
- 1,400 lbf = 6,227.51 N
- 1,425 lbf = 6,338.716 N
- 1,450 lbf = 6,449.921 N
- 1,475 lbf = 6,561.127 N
- 1,500 lbf = 6,672.332 N
- 1,525 lbf = 6,783.538 N
- 1,550 lbf = 6,894.744 N
- 1,575 lbf = 7,005.949 N
- 1,600 lbf = 7,117.155 N
- 1,625 lbf = 7,228.36 N
- 1,650 lbf = 7,339.566 N
- 1,675 lbf = 7,450.771 N
- 1,700 lbf = 7,561.977 N
- 1,725 lbf = 7,673.182 N
- 1,750 lbf = 7,784.388 N
- 1,775 lbf = 7,895.593 N
- 1,800 lbf = 8,006.799 N
- 1,825 lbf = 8,118.004 N
- 1,850 lbf = 8,229.21 N
- 1,875 lbf = 8,340.416 N
- 1,900 lbf = 8,451.621 N
- 1,925 lbf = 8,562.827 N
- 1,950 lbf = 8,674.032 N
- 1,975 lbf = 8,785.238 N
- 2,000 lbf = 8,896.443 N
- 2,050 lbf = 9,118.854 N
- 2,100 lbf = 9,341.265 N
- 2,150 lbf = 9,563.676 N
- 2,200 lbf = 9,786.088 N
- 2,250 lbf = 10,008.499 N
- 2,300 lbf = 10,230.91 N
- 2,350 lbf = 10,453.321 N
- 2,400 lbf = 10,675.732 N
- 2,450 lbf = 10,898.143 N
- 2,500 lbf = 11,120.554 N
- 2,550 lbf = 11,342.965 N
- 2,600 lbf = 11,565.376 N
- 2,650 lbf = 11,787.787 N
- 2,700 lbf = 12,010.198 N
- 2,750 lbf = 12,232.609 N
- 2,800 lbf = 12,455.021 N
- 2,850 lbf = 12,677.432 N
- 2,900 lbf = 12,899.843 N
- 2,950 lbf = 13,122.254 N
- 3,000 lbf = 13,344.665 N
- 3,050 lbf = 13,567.076 N
- 3,100 lbf = 13,789.487 N
- 3,150 lbf = 14,011.898 N
- 3,200 lbf = 14,234.309 N
- 3,250 lbf = 14,456.72 N
- 3,300 lbf = 14,679.131 N
- 3,350 lbf = 14,901.542 N
- 3,400 lbf = 15,123.953 N
- 3,450 lbf = 15,346.365 N
- 3,500 lbf = 15,568.776 N
- 3,550 lbf = 15,791.187 N
- 3,600 lbf = 16,013.598 N
- 3,650 lbf = 16,236.009 N
- 3,700 lbf = 16,458.42 N
- 3,750 lbf = 16,680.831 N
- 3,800 lbf = 16,903.242 N
- 3,850 lbf = 17,125.653 N
- 3,900 lbf = 17,348.064 N
- 3,950 lbf = 17,570.475 N
- 4,000 lbf = 17,792.886 N
- 4,050 lbf = 18,015.298 N
- 4,100 lbf = 18,237.709 N
- 4,150 lbf = 18,460.12 N
- 4,200 lbf = 18,682.531 N
- 4,250 lbf = 18,904.942 N
- 4,300 lbf = 19,127.353 N
- 4,350 lbf = 19,349.764 N
- 4,400 lbf = 19,572.175 N
- 4,450 lbf = 19,794.586 N
- 4,500 lbf = 20,016.997 N
- 4,550 lbf = 20,239.408 N
- 4,600 lbf = 20,461.819 N
- 4,650 lbf = 20,684.231 N
- 4,700 lbf = 20,906.642 N
- 4,750 lbf = 21,129.053 N
- 4,800 lbf = 21,351.464 N
- 4,850 lbf = 21,573.875 N
- 4,900 lbf = 21,796.286 N
- 4,950 lbf = 22,018.697 N
- 5,000 lbf = 22,241.108 N
- 5,100 lbf = 22,685.93 N
- 5,200 lbf = 23,130.752 N
- 5,300 lbf = 23,575.575 N
- 5,400 lbf = 24,020.397 N
- 5,500 lbf = 24,465.219 N
- 5,600 lbf = 24,910.041 N
- 5,700 lbf = 25,354.863 N
- 5,800 lbf = 25,799.685 N
- 5,900 lbf = 26,244.508 N
- 6,000 lbf = 26,689.33 N
- 6,100 lbf = 27,134.152 N
- 6,200 lbf = 27,578.974 N
- 6,300 lbf = 28,023.796 N
- 6,400 lbf = 28,468.618 N
- 6,500 lbf = 28,913.44 N
- 6,600 lbf = 29,358.263 N
- 6,700 lbf = 29,803.085 N
- 6,800 lbf = 30,247.907 N
- 6,900 lbf = 30,692.729 N
- 7,000 lbf = 31,137.551 N
- 7,100 lbf = 31,582.373 N
- 7,200 lbf = 32,027.196 N
- 7,300 lbf = 32,472.018 N
- 7,400 lbf = 32,916.84 N
- 7,500 lbf = 33,361.662 N
- 7,600 lbf = 33,806.484 N
- 7,700 lbf = 34,251.306 N
- 7,800 lbf = 34,696.129 N
- 7,900 lbf = 35,140.951 N
- 8,000 lbf = 35,585.773 N
- 8,100 lbf = 36,030.595 N
- 8,200 lbf = 36,475.417 N
- 8,300 lbf = 36,920.239 N
- 8,400 lbf = 37,365.062 N
- 8,500 lbf = 37,809.884 N
- 8,600 lbf = 38,254.706 N
- 8,700 lbf = 38,699.528 N
- 8,800 lbf = 39,144.35 N
- 8,900 lbf = 39,589.172 N
- 9,000 lbf = 40,033.995 N
- 9,100 lbf = 40,478.817 N
- 9,200 lbf = 40,923.639 N
- 9,300 lbf = 41,368.461 N
- 9,400 lbf = 41,813.283 N
- 9,500 lbf = 42,258.105 N
- 9,600 lbf = 42,702.928 N
- 9,700 lbf = 43,147.75 N
- 9,800 lbf = 43,592.572 N
- 9,900 lbf = 44,037.394 N
- 10,000 lbf = 44,482.216 N
この係数は二つの厳密な定義から出ます。ポンドが0.45359237キログラム、標準重力加速度が9.80665メートル毎秒毎秒で、後者は1901年の第3回国際度量衡総会が定めました。両者の積は4.4482216152605ニュートンで、丸めは入りません。 算出方法と出典.
よくある質問
lbとlbfはどう違いますか。
ポンドは質量、重量ポンドはその質量が標準重力のもとで示す重さです。1ポンドは正確に0.45359237キログラム、1重量ポンドは正確に4.4482216152605ニュートンです。米国の仕様書は両方をlbと書くことが多く、質量をlbm、力をlbfと書き分ける場合もありますが、どちらを指すかは前後の文が決めます。
スラグとパウンダルとは何ですか。
フィートとポンドで数えながら力学のつじつまを合わせる二つの方法です。スラグは1重量ポンドが毎秒毎秒1フィートだけ加速させる質量で、14.5939キログラム、つまり32.174ポンドにあたります。パウンダルはその逆で、1ポンドを毎秒毎秒1フィート加速させる力であり、わずか0.1383ニュートンです。米国の工学では両側にポンドを残し、gcと書く32.174の定数を持ち歩くほうが多く見られます。
4,000 lbと表示されたスリングは何を保証しますか。
使用荷重であって破断荷重ではありません。米国の吊り具は使用荷重WLLをポンドで表示し、規格ASME B30.9は繊維スリングに安全率5を求めます。したがって破断は20,000ポンド、つまり89キロニュートン付近です。欧州規格EN 1492は安全率7を採り、同じ内容をキログラムで印字するため、安全率まで換算しないと二枚のラベルは比べられません。
50ポンドとうたう磁石は本当に50ポンドを保持しますか。
まれです。表示の吸着力50ポンド、すなわち222ニュートンは理想条件での測定値です。塗装も隙間もない直接接触、厚い軟鋼板、面に垂直な引き上げが前提になります。薄い鋼板、塗装の層、斜めの引き剥がしがあれば値は半分以下になり、横滑りへの耐力は表示された吸着力の一部にすぎません。
1ポンドより小さい力はどう書きますか。
重量オンス、重量グラム、あるいはセンチニュートンで書きます。1重量オンスは0.2780ニュートン、1重量グラムは0.00980665ニュートンです。小さな機構の言葉で、メカニカルキーボードのスイッチは45重量グラム、つまり0.44ニュートンや1.6重量オンスと表示されます。ばね、マイクロスイッチ、剥離試験にも同じ単位が使われます。