Twisted Rope, Line, and Twine

yellow twisted poly

Twisted rope is the simplest and the oldest type.

It’s made in essentially the same way today as it was thousands of years ago - by twisting a bunch of fibers or yarns together to form a strand, then taking three or so of these strands and twisting them together in the opposite direction.

When long lengths of twisted rope were required for a tall mast or to hoist a load to a high place, they were formed - by hand or later with machines - in a 'rope walk' as long as the finished dimension, in order to avoid splices. To the same end, abandoned chicken coops are sometimes converted into rope making factories.

Natural fiber cordage for general use - mostly made from manila or cotton was the ‘state-of-the-art’ until the mid-twentieth century, when nylon rope was introduced. With it's superior strength, rot resistance, chemical resistance and ability to absorb shock loads, nylon twisted rope was soon replacing manila and cotton in farm, industrial, and military cordage applications. Since that time, polyester and other synthetic fibers have been developed and used to produce a variety of specialty products, matching the strengths of the individual - and in some cases multiple - fibers to the needs of the work to be done.

Manila, the previously 'state of the art' working rope, is now - with few exceptions - recommended just for decorative use. Manila should not be used for overhead lifting or when failure could lead to damage to people or property.

As far as long term use, especially outdoors, Manila and any other natural fiber ropes will eventually rot. If it is stored wet, or if it does not dry out completely after getting wet, the fibers will rot - not visibly, but on the inside - and the rope will break without warning.

Properties of 3 Strand Twisted Ropes

Size Polypropylene Nylon Polyester Composite Manila
Diameter (inches) Circum- ference (Inches) New Rope Breaking Strength Lbs Working Load Limit Range Lbs New Rope Breaking Strength Lbs Working Load Limit Range Lbs New Rope Breaking Strength Lbs Working Load Limit Range Lbs New Rope Breaking Strength Lbs Working Load Limit Range Lbs New Rope Breaking Strength Lbs Working Load Limit Range Lbs
3/16 5/8 650 54-130 880 73-176 765 63-153 - - - -
1/4 3/4 1,125 94-225 1,485 124-298 1,315 110-263 1,200 100-240 540 45-61
5/16 1 1,710 143-342 2,295 192-460 2,050 171-410 1,870 156-374 900 75-95
3/8 1-1/8 2,430 203-486 3,240 270-648 2,900 242-580 2,700 225-540 1,215 101-136
1/2 1-1/2 3,780 315-756 5,670 473-1130 5,085 424-1,017 4,400 367-880 2,385 199-268
5/8 2 5,580 465-1,116 8,910 743-1,780 7,825 652-1,565 6,100 508-1,220 3,960 330-446
3/4 2-1/4 7,650 638-1,530 12,780 1,065-2556 11,200 933-2,240 8,400 700-1680 4,860 405-546
7/8 2-3/4 10,350 863-2,070 17,280 1,440-3,460 15,225 1,269-3,045 11,125 927-2,225 6,930 578-780
1 3 12,825 1,069-2,565 22,230 1,850-4,400 19,775 1,648-3,955 13,175 1,098-2,635 8,100 675-911
1-1/4 3-3/4 19,350 1,613-3,870 34,830 2,900-6,960 29,800 2,483-5,960 19,900 1,658-3,980 12,150 1,013-1,366
1-1/2 4-1/2 27,350 2,279-5,470 48,600 4,050-9,720 42,200 3,517-8,440 28,250 2,354-5,650 16,650 1,388-1,873
2 6 46,800 3,900-9,360 84,600 7,050-16,900 72,000 6,000-14,400 48,050 4,004-9,610 27,900 2,325-3,139

WORKING LOAD LIMITS

The Working Load is the weight or force applied to a rope in a given application.

Working Load Limits (WLL) are guidelines for the maximum weight or force capacity of a given rope in general use.

Working Load Limits are calculated, using an application based Design Factor, as a percentage of the breaking strength of new, unused rope.

Again – the Working Load Limits shown are guidelines, not specifications, and are for non-critical applications. They do not apply if the rope is to be used for overhead lifting, or if life, limb, or property is at risk. In these cases - or for more complete information on determination of Design Factor and WLL - please refer to the Cordage Institute "Safer Use of Fiber Rope".

Manila Rope

Twisted Composite Fiber

Twisted Nylon

Twisted Polyester

Twisted Polypropylene

Return from Twisted Rope to Home Page