Found this.
See thread = http://www.bushcraftuk.com/forum/showthread.php?t=34834
Breaking strains
Taking a three lay rope of 1" [2.5 cm] diameter as standard, the following table of breaking strains may
serve to give a fair idea of general strengths of various materials. For safety sake always regard the
lowest figure as the breaking strain unless you know otherwise.
Green Grass 100 lbs. to 250 lbs. [45 kg to 115 kg]
Bark Fibre 500 lbs. to 1,500 lbs. [225 kg to 680 kg]
Palm Fibre 650 lbs. to 2,000 lbs. [295 kg to 905 kg]
Sedges 2,000 lbs. to 2,500 lbs. [905 kg to 1,135 kg]
Monkey Rope (Lianas) 560 lbs. to 700 lbs. [245 kg to 320 kg]
Lawyer Vine (Calamus) 1⁄2" [1.25 cm] dia. 1,200 lbs. [545 kg]
Double the diameter quadruples the breaking strain. Halve the diameter, and you reduce the breaking
strain to one fourth.
See thread = http://www.bushcraftuk.com/forum/showthread.php?t=34834
Breaking strains
Taking a three lay rope of 1" [2.5 cm] diameter as standard, the following table of breaking strains may
serve to give a fair idea of general strengths of various materials. For safety sake always regard the
lowest figure as the breaking strain unless you know otherwise.
Green Grass 100 lbs. to 250 lbs. [45 kg to 115 kg]
Bark Fibre 500 lbs. to 1,500 lbs. [225 kg to 680 kg]
Palm Fibre 650 lbs. to 2,000 lbs. [295 kg to 905 kg]
Sedges 2,000 lbs. to 2,500 lbs. [905 kg to 1,135 kg]
Monkey Rope (Lianas) 560 lbs. to 700 lbs. [245 kg to 320 kg]
Lawyer Vine (Calamus) 1⁄2" [1.25 cm] dia. 1,200 lbs. [545 kg]
Double the diameter quadruples the breaking strain. Halve the diameter, and you reduce the breaking
strain to one fourth.