Document Xz0856ayLJ9rpk95rw8Jrxxx4

ROPES, CHAINS, AND SLINGS wire rope manufacturers be consulted for the most suitable type. Some service conditions require rope with special qualities. Fiber cores are affected by temperatures above 212 F, under such conditions, a metallic core provides greater efficiency and safety A zinc-coated or stain less steel wire rope effectively resists some types of comsion Specific corrosion prob lems should be referred to a wire rope manufacturer. Since preformed wire rope does not un ravel, it has advantages for certain services, such as for slings and on construction and similar heavy equipment Preformed rope is less likely to set or kink, and broken wires do not protrude to create a hazard to the hands of workmen However, closer in spection is necessary to detect broken wires. It is recommended that hoisting rope have at least the strength of "unproved plow steel" grade For many applications "extra unproved plow steel" grade, which is great est in strength, should be used to provide an adequate factor of safety, and better Fig. 21-1. Wire rope is made from large numbers of individual wires, most of which are not exposed. This, plus the fact that wires are continuous in any given length of rope, accounts for the high de gree of dependability and uniformity. Cross sections show usual 4x19 rope con taining 114 wires (left), and 4x37 classi fication rope made up of 313 separate wires (at right). Courteiy John A RoobJing'i Sont Corp t Subiidmry of Tne Colorado Fuel and Iron Corp service. It resists abrasion, shock, vibration, and fatigue (Table 21-D). TABLE 21-D BREAKING STRENGTH IN TONS OF IMPROVED PLOW STEEL (IPS) AND EXTRA IMPROVED PLOW STEEL (EIPS) ROPES Diameter (10 ) % %e % %%9 6 x 19 Classification IPS EIPS FO IWRO IWKC 610 827 10.70 1350 18.70 656 8.89 1150 14 50 17 90 755 1020 1330 16.80 20 60 6 x 87 Classification 8 x 19 Classification IPS EIPS IPS FO rwBG rwEc FC 577 7.82 1020 1290 1580 620 8 41 1100 1390 1700 714 967 12 60 1500 19.60 524 7.09 9.23 1160 14.30 % % i * i% 2380 25 60 32 20 34 60 4180 44 90 5260 S650 64 60 6940 29 40 3960 5170 65.00 79 90 22 60 24 30 30 60 3290 39 80 4280 SO 10 53.90 61.50 6610 2790 37 80 49.10 6190 7610 20.50 27.70 36.00 45.30 55 70 x% 7770 83 50 9600 7410 7970 9170 67.10 IK 9200 98 90 11400 8790 94 50 109 00 7940 1% 10700 11500 132 00 10300 11100 12700 e e e 1% 124 00 133 00 153 00 119.00 128 00 14600 e e 1% 141 00 152 00 174 00 13600 14600 168.00 -- 16000 17200 198 00 254 00 16500 29000 2K 179 00 192 00 22100 17300 18600 21400 2Vt 20000 21500 247 00 193 00 20700 23900 22-5