Rope Fiber Selection Guide: Fiber Properties and Typical Values
Manila
Sisal
Cotton
Nylon
Polyester
Polypropylene
Polyethylene
Kevlar1*
Spectra2*
STRENGTH:
Breaking Tenacity–
(grams/denier)
5.0-6.0
4.0-5.0
2.0-3.0
7.0-9.5
7.0-9.5
6.5
6.0
18-26.5
30.0
Wet Strength vs.
Dry Strength
Up to 120%
Up to
120%
Up to 120%
85-90%
100%
100%
100%
95%
100%
Shock-load
Absorption Ability
Poor
Poor
Very Poor
Excellent
Good
Very Good
Fair
Poor
Fair
WEIGHT: Specific Gravity
1.38
1.38
1.54
1.14
1.38
0.91
0.95
1.44
0.97
Floats
No
No
No
No
No
Yes
Yes
No
Yes
ELONGATION:
Percent at Break
10-12%
10-12%
5-12%
18-25%
12-15%
15-25%
15-25%
1.5-3.6%
3.5%
Creep (extension under sustained load)
Very Low
Very Low
Very Low
Moderate
Low
High
High
Very Low
Moderate
EFFECTS OF MOISTURE:
Water Absorp. of Individual Fibers
Up to 100%
Up to 100%
Up to 100%
2-8%
< 1%
None
None
3.5-7.0%
None
Dielectric Properties
Very Poor
Very Poor
Very Poor
Poor
Good
Excellent
Excellent
Poor
Excellent
DEGRADATION:
Resistance to UV
in Sunlight
Good
Good
Good
Good
Excellent
Poor
(black is best)
Fair
(black is best)
Fair
Fair
Resistance to
Rot and Mildew
Poor
Poor
Poor
Excellent
Excellent
Excellent
Excellent
Excellent
Excellent
Storage Requirements
Dry only
Dry only
Dry only
Wet
or Dry
Wet
or Dry
Wet
or Dry
Wet
or Dry
Wet
or Dry
Wet
or Dry
ROPE ABRASION RESISTANCE:
Surface
Good
Fair
Poor
Very Good
Excellent
Good
Good
Fair
Very Good
Internal
Fair
Fair
Fair
Excellent
Excellent
Good
Good
Poor
Excellent
THERMAL PROPERTIES:
Melts at
Does not melt,
Chars at 350°
Does not melt,
Chars at 350°
Does not melt,
Chars at 350°
420-480°
490-500°
330°
275°
800°
-Begins
to de-
compose
297°
RESISTANCE 3*:
Resistance to Acids
Poor
Poor
Poor
Fair
Good
Excellent
Excellent
Fair
Excellent
Resistance to Alkalis
Poor
Poor
Fair
Very Good
Fair
Excellent
Excellent
Fair
Excellent
Resistance to Oils
and Gas
Poor
Fair
Poor
Very Good
Very Good
Very Good
Very Good
Very Good
Very Good
1* Based on DuPont
Kevlar® data
2* Based on Allied-Signal Spectra® data-Type
900
3* Resistance is relative to the length of
exposure, percent of concentration and temperature.
CAUTION: Use of Working Loads
Because of the wide range of rope use, rope condition, and exposure to the
various factors affecting the rope, it is impossible to make blanket
recommendations as to the correct choice of rope to use. However, we have
provided the tensile strength for each diameter and type of rope. These
strengths are based on tests of new and unused rope, with appropriate
splices. Proper choice, care and inspection of the rope are essential for
reasonably safe use of the rope. Consult your cordage vendor for proper
use.
Dynamic Loading Voids Normal Works Loads
Dynamic Loading occurs when rope is subjected to sudden or extreme stress.
Figures given as working loads are void if rope has been subjected to
dynamic loading, high temperatures, long periods of load, extreme stress,
improper use or storage.
Effect of Temperature on Tensile Strength
The tensile strength charts apply to ropes tested at normal room
temperature (70°F). Ropes have lower tensile strength at higher
temperatures. Continued exposure at elevated temperatures causes permanent
damage.
WARNING! MISUSE OF ROPES COULD RESULT IN SERIOUS INJURY.