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Axial Load Rating:
Basic static axial load rating
Basic dynamic axial load rating
Axial rigidity/stiffness/spring rate

 
BASIC STATIC AXIAL LOAD RATING   Back to top

provides the Allowable Axial Load of the Ball Screw:

Where:

            fs=1…2 (normal motion) and fs=2…3 (shock motion)
Nominal Diameter d0(mm) Nominal Lead Ph0 (mm) Ball Diameter (mm) Basic Static Axial Load Rating Coa (daN)
2 3 4 5 6
12 4 2,500 367 548 731 913 1096
16 4 2,500 546 816 1088 1360 1632
5 3,175 595 888 1184 1480 1776
20 5 3,175 824 1233 1643 2054 2465
25 5 3,175 1113 1666 2221 2777 3332
10 6,350 1691 2515 3354 4192 5031
32 5 3,175 1519 2275 3033 3792 4550
10 6,350 2379 3552 4736 5919 7103
40 5 3,175 1983 2973 3963 4954 5945
10 6,350 3297 4930 6574 8217 9861
50 5 3,175 2565 3846 5128 6409 7691
10 6,350 4452 6664 8885 11107 13328
63 5 3,175 3322 4982 6642 8303 9963
10 6,350 6071 9094 12126 15157 18188
12 7,939 6961 10422 13896 17370 20845
16 9,525 7937 11867 15823 19779 23734
80 10 6,350 7933 11890 15854 19817 23781
12 7,939 9494 14225 18967 23709 28451
16 9,525 11052 16544 22059 27573 33088
20 12,700 13189 19721 26295 32869 39443
100 10 6,350 10260 15383 20510 25638 30765
12 7,939 12400 18587 24782 30978 37173
16 9,525 14701 22024 29365 36706 44047
20 12,700 17806 26656 35541 44426 53312
24 15,875 20608 30822 41096 51370 61644
125 10 6,350 13057 19580 26106 32633 39159
12 7,939 16038 24045 32060 40075 48090
16 9,525 18892 28314 37753 47191 56629
20 12,700 23376 35018 46691 58364 70036
24 15,875 27823 41656 55542 69427 83313
160 10 6,350 17250 25871 34494 43118 51741
12 7,939 21135 31693 42258 52822 63387
16 9,525 24661 36972 49296 61621 73945
20 12,700 31733 47561 63415 79269 95123
24 15,875 37964 56881 75841 94801 113762
32 19,050 44207 66176 88235 110294 132352
180 16 9,525 28326 42472 56629 70787 84944
20 12,700 36385 54544 72725 90907 109088
24 15,875 43770 65596 87462 109327 131193
32 19,050 50491 75615 100820 126026 151231
 

 

BASIC DYNAMIC AXIAL LOAD RATING

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provide the the Basic Rating Life (Expected Life):

where: 
           fr=1...1,2  (smooth motion),
           fr=1,2...1,5  (normal motion),
           fr=1,5...2,0  (shock motion),
           Fa- Axial Constant Load - including force and external force, if Fa varies this variable must be placed with Fm - Average Axial Load
Nominal diameter d0 (mm) Pitch

Pho (mm)

 Ball Diameter (mm) Basic Dynamic Axial Load Ca (daN)
2 3 4 5 6
12 4 2,500 237 336 430 521 609
16 4 2,500 293 415 532 644 754
5 3,175 363 514 658 798 933
20 5 3,175 433 613 785 952 1113
25 5 3,175 502 712 912 1105 1292
10 6,350 1034 1466 1878 2275 2661
32 5 3,175 580 822 1052 1275 1492
10 6,350 1263 1790 2293 2778 3249
40 5 3,175 651 923 1182 1432 1675
10 6,350 1507 2136 2735 3314 3876
50 5 3,175 725 1027 1315 1594 1864
10 6,350 1749 2479 3175 3847 4500
63 5 3,175 804 1140 1460 1769 2069
10 6,350 2027 2873 3679 4457 5214
12 7,939 2611 3701 4740 5742 6717
16 9,525 3235 4585 5871 7114 8321
80 10 6,350 2267 3214 4116 4986 5833
12 7,939 3019 4278 5479 6638 7765
16 9,525 3813 5403 6920 8384 9807
20 12,700 5247 7437 9524 11539 13498
100 10 6,350 2524 3577 4581 5550 6492
12 7,939 3390 4804 6153 7454 8720
16 9,525 4348 6163 7893 9562 11186
20 12,700 6092 8633 11057 13396 15670
24 15,875 7844 11116 14237 17248 20176
125 10 6,350 2775 3932 5036 6102 7137
12 7,939 3773 5347 6848 8297 9705
16 9,525 4829 6843 8764 10618 12421
20 12,700 6896 9773 12516 15164 17738
24 15,875 9105 12904 16526 20022 23421
160 10 6,350 3103 4397 5632 6823 7982
12 7,939 4216 5975 7652 9271 10844
16 9,525 5368 7608 9744 11805 13809
20 12,700 7896 11190 14331 17363 20311
24 15,875 10508 14892 19072 23106 27029
32 19,050 13276 18816 24097 29195 34151
180 16 9,525 5687 8059 10321 12505 14628
20 12,700 8363 11852 15179 18390 21511
24 15,875 11186 15852 20302 24597 28773
32 19,050 14072 19943 25541 30944 36197
 

 

AXIAL RIGIDITY / STIFFNESS / SPRING RATE

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for the ball screw assembly composed of ball screw, nuts and balls and the system made by double flanged preloaded nuts with the proload standard force (Fpr) amount equal of 10% of the Basic Dynamic Axial Load (Ca):

Where according ISO 3408-3:1992:

           Fa - the axial loads applied-equivalent to 0,5xFpr and 2xFpr, 

         - the axial elastic displacement.

The Total Axial Rigidity (R) is given by the general equation:

Where:
         Rbs - rigidity of the ball screw,
         Rnu - rigidity of the nuts unit,
         Rb/t - rigidity of balls in the contact area,
         RB - rigidity of the bearings and housings,
         RSB - rigidity of the nut bracket/support.

Nominal Diameter d0 (mm) Lead Ball diameter (mm)  Axial Rigidity
Ph0 (mm) Rnu (daN/μm)
2 3 4 5 6
12 4 2,500 20 16 38 47 56
16 4 2,500 27 22 52 64 76
5 3,175 25 20 48 59 70
20 5 3,175 31 26 61 76 90
25 5 3,175 39 33 76 94 112
10 6,350 35 29 69 85 101
32 5 3,175 48 41 93 115 137
10 6,350 46 38 89 110 131
40 5 3,175 57 49 111 137 163
10 6,350 58 49 113 140 167
50 5 3,175 65 58 127 158 188
10 6,350 71 61 138 171 204
  5 3,175 75 69 146 181 216
63 10 6,350 87 76 169 210 250
12 7,939 88 75 171 212 253
16 9,525 89 75 173 214 255
80 10 6,350 102 91 199 247 294
12 7,939 107 93 208 257 307
16 9,525 114 97 222 275 327
20 12,700 112 93 217 269 320
100 10 6,350 115 107 226 280 334
12 7,939 124 112 242 300 358
16 9,525 136 118 264 328 390
20 12,700 137 116 266 329 392
24 15,875 135 114 263 325 388
125 10 6,350 126 122 247 307 366
12 7,939 142 132 277 343 410
16 9,525 158 140 308 381 454
20 12,700 163 141 316 392 467
24 15,875 167 143 324 401 478
160 10 6,350 140 141 274 340 406
12 7,939 158 153 309 384 458
16 9,525 184 168 359 446 531
20 12,700 197 175 384 476 567
24 15,875 205 179 399 494 589
32 19,050 215 184 419 519 618
180 16 9,525 199 184 389 482 575
20 12,700 214 193 418 518 618
24 15,875 225 198 437 542 646
32 19,050 237 203 461 571 680
 

 

Note: For general applications, because the values given in the table do not include the rigidity of the bracket / support of nuts, in this situation please take a value of 80% ... 90% of those shown in the table. 
 
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