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rope characteristics
    Manila Nylon Polyester Polypropylene Spectra
  Strength Fair Excellent Excellent Very good Excellent
Working Characteristics Shock load Poor Excellent Good Very good Fair
Surface abrasion Good Very good Excellent Fair Fair
Elasticity Fair Excellent Good Good Fair
Floats No No No Yes No
           
Resistance to the following conditions

 

 Rot & Mildew Poor Excellent Excellent Excellent Excellent
Sunlight Good Good Excellent Poor Excellent
Oil & Gas Fair Excellent Excellent Very good Very good
Acids Poor Poor Good Good Good
Alkalies Poor Very good Good Excellent Good

                                              

service life factors
    Manila Sisal Nylon Polyester Polypropylene Polyextra
Service life factor Manila = 1   1 .3 4-5 3-5 2-3 2-4
Cost per lb. Manila = 100   100 55 187 178 102 153
Cost per ft.    Manila = 100   100 55 179 201 68 126
Cost per ft with service life factor manila = 100   100 68 51 50 27 42
Cost per ft. with  working strength factor Manila = 100 100 69 113 163 52 117
Cost per ft. with both working strength and service life factors factors     Manila = 100   100 87 32 40 21 39

NOTE: THE Information above is general and is provided with the intention of making it easier to select the cord or rope you need.  When making your selection be sure to apply sound engineering practices.

w/l/l

Work Load Limits are determined by dividing breaking strength by a design factor.  Working Load Limits listed are based on a median design factor of 8.  Below is a table of reference factors.

critical conditions to consider
1)  Small ropes are more effected by cutting,  abrasion and UV.     8)  Possibility that temperatures higher than fiber limits may be present.
2)  Dynamic loads are not accurately known. 9)  Hazardous chemicals may be present.
3)  Operators are possibly unfamiliar with rope characteristics 10)  Ropes are sometime kept in service longer than safe limits.
4)  Operation / use procedures are not well defined or controlled. 11)  If tension is on the rope for long periods.
5)  How often is rope inspected? 12)  Rope will be subjected to sharp bends, or used over pulleys or surfaces with too small a radius.
6)  Abrasion, cutting surfaces and dirt may be present. 13)  Knots reduce the strength by up to 50%
7)  Shock loads or extreme dynamic loads may possibly occur. 14)  Death, injury, or loss of valuable property may result if rope fails.
 

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