| Nominal Size (1) |
Linera
Density (2) |
New Rope Min.
Breaking Strength (3) |
Design
Factor
Range (4) |
Working Load
Limit Ranges (5) lbs. |
| Diameter |
Size No. |
| In. |
(mm) |
Circ. (In.) |
Lbs./100 |
Lbs. |
1/12 - 1/5 |
| 3/16* |
5 |
9/16 |
1.37 |
405 |
12 - 5 |
34 - 81 |
| 1/4 |
6 |
3/4 |
1.82 |
540 |
12 - 5 |
45 - 108 |
| 5/16 |
8 |
1 |
2.64 |
900 |
12 - 5 |
75 - 180 |
| 3/8 |
10 |
1-1/8 |
3.79 |
1215 |
12 - 5 |
101 - 243 |
| 7/16* |
11 |
1-1/4 |
4.87 |
1575 |
12 - 5 |
131 - 315 |
| 1/2 |
12 |
1-1/2 |
6.96 |
2385 |
12 - 5 |
199 - 477 |
| 9/16* |
14 |
1-3/4 |
9.63 |
3105 |
12 - 5 |
259 - 621 |
| 5/8 |
16 |
2 |
12.7 |
3960 |
12 - 5 |
330 - 792 |
| 3/4 |
18 |
2-1/4 |
15.9 |
4860 |
12 - 5 |
405 - 972 |
| 13/16* |
20 |
2-1/2 |
18.6 |
5850 |
12 - 5 |
488 - 1170 |
| 7/8 |
22 |
2-3/4 |
21.4 |
6930 |
12 - 5 |
578 - 1386 |
| 1 |
24 |
3 |
25.7 |
8100 |
12 - 5 |
675 - 1620 |
| 1-1/16* |
26 |
3-1/4 |
29.8 |
6450 |
12 - 5 |
788 - 1890 |
| 1-1/8 |
28 |
3-1/2 |
34.3 |
10800 |
12 - 5 |
900 - 2160 |
| 1-1/4 |
30 |
3-3/4 |
39.7 |
12150 |
12 - 5 |
1013 - 2430 |
| 1-3/8* |
32 |
4 |
45.6 |
13500 |
12 - 5 |
1125 - 2700 |
| 1-1/2 |
36 |
4-1/2 |
57.0 |
16650 |
12 - 5 |
1388 - 3330 |
| 1-5/8* |
40 |
5 |
71.1 |
20250 |
12 - 5 |
1688 - 4050 |
| 1-3/4* |
44 |
5-1/2 |
85.0 |
23850 |
12 - 5 |
1988 - 4770 |
| 2 |
48 |
6 |
102 |
27900 |
12 - 5 |
2325 - 5580 |
| 2-1/8* |
52 |
6-1/2 |
120 |
32400 |
12 - 5 |
2700 - 6480 |
| 2-1/4* |
56 |
7 |
139 |
36900 |
12 - 5 |
3075 - 7380 |
| 2-1/2* |
60 |
7-1/2 |
164 |
42300 |
12 - 5 |
3525 - 8460 |
| 2-5/8* |
64 |
8 |
182 |
46800 |
12 - 5 |
3900 - 9360 |
| 2-7/8* |
68 |
8-1/2 |
215 |
54900 |
12 - 5 |
4575 - 10980 |
| 3* |
72 |
9 |
230 |
57500 |
12 - 5 |
4792 - 11500 |
| 3-1/4* |
80 |
10 |
284 |
69500 |
12 - 5 |
5792 - 13900 |
| 3-5/8* |
88 |
11 |
349 |
81900 |
12 - 5 |
6825 - 16280 |
| 4* |
96 |
12 |
414 |
24500 |
12 - 5 |
7875 - 18900 |
(1) Diameter is approximate and is actually determined by linear density. See CI 1401 (current). See Safe Use Guidelines.
(2) Linear density is considered standard. Tolerances are ±10% for 3/16" - 5/16" dia. inclusive; ±8% for 3/8" - 9/16" dia. inclusive; ±5% for† 5/8" dia. and up.
(3) New rope Minimum Breaking Strength (MBS) is based on data from a number of manufacturers and represents a value of 2 standard deviations below the mean, established by regression analysis.
(4) For critical applications, refer to Safe Use Guidelines CI-1401(current).
(5) Working Load Limit (WLL) is determined by dividing the new rope Minimum Breaking Strength by the selected Design factor. Important information is given in CI-1401(current).
Asterisk next to diameter in chart indicates a non-stock size and may take up to 4 months to supply.
NOTE: The working load of a rope shall be determined by dividing the minimum breaking strength by the design factor. For critical applications a design factor greater than 12 may be necessary. Users must determine the design factor as they are the only ones who can assess service conditions and establish operating procedures. If uncertain, contact a qualified engineering consultant for assistance. IN ALL CONDITIONS WHERE THERE IS RISK TO LIFE, THE WORKING LOAD SHOULD BE SUBSTANTIALLY REDUCED AND THE ROPE INSPECTED FREQUENTLY. Cf. Cordage Institute FIBER ROPE TECHNICAL INFORMATION AND APPLICATION MANUAL CIB 1.4 9701
CAUTION: USE OF WORKING LOADS
Because of the wide range of rope use, rope conditions, exposure to several factors affecting rope behavior, and the degree of risk to life and property involved, it is impossible to make blanket recommendations as to working loads. However, to provide guidelines, working loads are tabulated for rope in good condition with appropriate splices, in non-critical applications and under normal service conditions.
A higher working load may be selected only with expert knowledge of conditions and professional estimate of risk and if the rope has not been subject to dynamic loading or other excessive use.
You should not use a rope at high working loads if it has previously experienced excessive use, high dynamic loading, sustained loading for long periods, and exposure to high temperatures. For all such applications and for applications involving more severe exposure conditions, or for recommendations on special applications, consult an expert in the specific field where the rope is to be used.
Examples of ropes that are commonly subjected to dynamic loading are towing lines, life lines, hoisting ropes, safety lines, climbing ropes, etc... In such applications, working loads as given do not apply.
Note: Rope tensile strengths are based on tests of new and unused rope of standard construction in accordance with the required specifications. The information is intended as a guide only. As mentioned, a thorough engineering analysis of all conditions of use should be made specific to the application to ensure that the ropes are well suited for the job. More info on Working Loads |
