Alchem Incorporated
314 East 195th St.
Euclid, Ohio 44119
(216) 313-8674
alchem@en.com
We currently manufacture a number of different crossbow prod models to provide our customers with a wide range of draw weights. We have determined that average draw weights will vary slightly from production batch to production batch due to differences in the thickness of the metal, the chemistry of the steel and its resulting hardness. Furthermore, draw weights will vary even within a given batch due to minor differences in the shape (tillering) of the parts. In the past these variations caused our customers a great deal of consternation. One of our customers, by the name of Gene Dwiggins of Rhode Island, built us a testing bench capable of rapidly and accurately determining the draw weight of a prod up to 300 pounds. Therefore we now test every prod we produce and record on its center belly the draw weight determined at 11.5 inches. This information makes it possible for a customer to order the exact draw weight desired. It also makes it possible to estimate the approximate draw weight and energy storage of a given prod when drawn to a distance shorter than the maximum recommended 11.5 inches. For this reason we have devised the following table.

The following draw weight, draw length, and energy table has been compiled to include all of our prod models with a maximum recommended overall draw distance of 11.5 inches. In estimating draw weights and energies we assumed a brace height of 3.5 inches giving an actual maximum draw distance of 8 inches. Data was calculated down to 6 inches of actual draw since shorter draw lengths are not likely to be required by our customers. The following measurements are estimates.

Distances are expressed in inches. Weights are in pounds. It should be noted that the "pound inch" figures following Weight x Draw are not equivalent to energy expressed in inch-pounds.

The actual energy E required to draw a bow W a given distance D may be calculated as follows:

E = .5 x W x D.

W is the draw weight of the bow at distance D.



11.5" (8" draw) 11" (7.5" draw) 10.5" (7" draw) 10" (6.5" draw) 9.5" (6" draw)
Draw Weights 50 47 44 41 37
Weight x Draw 400 352 308 266 222
Inch Pounds 200 176 154 133 111
Draw Weights 55 52 48 45 41
Weight x Draw 440 390 336 292 246
Inch Pounds 220 195 168 146 123
Draw Weights 60 56 53 49 45
Weight x Draw 480 420 371 318 270
Inch Pounds 240 210 185 159 135
Draw Weights 65 61 57 53 49
Weight x Draw 520 457 399 344 294
Inch Pounds 260 228 199 172 147
Draw Weights 70 66 61 57 53
Weight x Draw 560 495 427 370 318
Inch Pounds 280 247 213 185 159
Draw Weights 75 70 66 61 56
Weight x Draw 600 525 462 396 336
Inch Pounds 300 262 231 198 168
Draw Weights 80 75 70 65 60
Weight x Draw 640 562 490 422 360
Inch Pounds 320 281 245 211 180
Draw Weights 85 80 74 69 64
Weight x Draw 680 600 518 448 384
Inch Pounds 340 300 259 224 192
Draw Weights 90 84 79 73 68
Weight x Draw 720 630 553 474 408
Inch Pounds 360 315 276 237 204
Draw Weights 95 89 83 77 71
Weight x Draw 760 667 581 500 426
Inch Pounds 380 333 290 250 213
Draw Weights 100 93 88 81 75
Weight x Draw 800 697 616 526 450
Inch Pounds 400 348 308 263 225
Draw Weights 105 98 92 85 79
Weight x Draw 840 735 644 552 474
Inch Pounds 420 367 322 276 237
Draw Weights 110 103 96 89 83
Weight x Draw 880 772 672 578 498
Inch Pounds 440 386 336 289 249
Draw Weights 115 108 101 93 86
Weight x Draw 920 810 707 604 516
Inch Pounds 460 405 353 302 258
Draw Weights 120 113 105 98 90
Weight x Draw 960 847 735 637 540
Inch Pounds 480 423 367 318 270
Draw Weights 125 117 109 102 94
Weight x Draw 1000 877 763 663 564
Inch Pounds 500 438 381 331 282
Draw Weights 130 122 114 106 98
Weight x Draw 1040 915 798 689 588
Inch Pounds 520 457 399 344 294
Draw Weights 135 127 118 110 101
Weight x Draw 1080 952 826 715 606
Inch Pounds 540 476 413 357 303
Draw Weights 140 131 123 114 105
Weight x Draw 1120 982 861 741 630
Inch Pounds 560 491 430 370 315
Draw Weights 145 136 127 118 109
Weight x Draw 1160 1020 889 767 654
Inch Pounds 580 510 444 383 327
Draw Weights 150 140 131 122 113
Weight x Draw 1200 1050 917 793 678
Inch Pounds 600 525 458 396 339
Draw Weights 155 145 136 126 116
Weight x Draw 1240 1087 952 819 696
Inch Pounds 620 543 476 409 348
Draw Weights 160 150 140 130 120
Weight x Draw 1289 1125 980 845 720
Inch Pounds 640 562 490 422 360
Draw Weights 165 155 144 134 124
Weight x Draw 1320 1162 1008 871 744
Inch Pounds 660 581 504 435 372
Draw Weights 170 159 149 138 128
Weight x Draw 1360 1192 1043 897 768
Inch Pounds 680 596 521 448 384
Draw Weights 175 164 153 142 131
Weight x Draw 1400 1230 1071 923 786
Inch Pounds 700 615 535 461 393
Draw Weights 180 169 158 146 135
Weight x Draw 1440 1230 1071 923 786
Inch Pounds 720 615 535 461 393
Draw Weights 185 173 162 150 139
Weight x Draw 1480 1297 1134 975 834
Inch Pounds 740 648 567 487 417
Draw Weights 190 178 166 154 143
Weight x Draw 1520 1335 1162 1001 858
Inch Pounds 760 667 581 500 429
Draw Weights 195 183 171 158 146
Weight x Draw 1560 1372 1197 1027 876
Inch Pounds 780 686 598 513 438
Draw Weights 200 188 175 163 150
Weight x Draw 1600 1410 1225 1059 900
Inch Pounds 800 705 612 529 450
Draw Weights 205 192 179 167 154
Weight x Draw 1640 1440 1253 1085 924
Inch Pounds 820 720 626 542 462
Draw Weights 210 197 184 170 158
Weight x Draw 1680 1477 1288 1105 948
Inch Pounds 840 738 644 552 474
Draw Weights 215 202 188 175 161
Weight x Draw 1720 1515 1316 1137 966
Inch Pounds 860 757 658 568 483
Draw Weights 220 206 193 179 165
Weight x Draw 1760 1545 1351 1163 990
Inch Pounds 880 772 675 581 495
Draw Weights 225 211 197 183 169
Weight x Draw 1800 1582 1379 1189 1014
Inch Pounds 900 791 689 594 507
Draw Weights 230 216 201 187 173
Weight x Draw 1840 1620 1407 1215 1038
Inch Pounds 920 810 703 607 519
Draw Weights 235 220 206 191 176
Weight x Draw 1880 1650 1442 1241 1056
Inch Pounds 940 825 721 620 528
Draw Weights 240 225 210 195 180
Weight x Draw 1920 1687 1470 1267 1080
Inch Pounds 960 843 735 633 540
Draw Weights 245 230 214 199 184
Weight x Draw 1960 1725 1498 1293 1104
Inch Pounds 980 862 749 646 552
Draw Weights 250 234 219 203 188
Weight x Draw 2000 1755 1533 1319 1128
Inch Pounds 1000 877 766 659 564