Parachute cord
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Parachute cord (also paracord or 550 cord) is a lightweight nylon kernmantle rope originally used in the suspension lines of US parachutes during World War II. Once in the field, paratroopers found this cord useful for many other tasks. It is now used as a general purpose utility cord by both military personnel and civilians. This versatile cord was even used by astronauts during STS-82, the twenty second Space Shuttle mission to repair the Hubble Space Telescope.[1]
The braided sheath has a high number of interwoven strands for its size, giving it a relatively smooth texture. The all-nylon construction makes paracord fairly elastic; depending on the application this can be either an asset or a liability.
While the U.S. military has no overall diameter requirements in its specifications, in the field 550 cord typically measures 5⁄32 inches (4 mm) in diameter.
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Military usage[edit]
Despite the historic association of pararopes with Airborne units and divisions, virtually all US units have access to the cord. It is used in almost any situation where light cordage is needed. Typical uses include attaching equipment to harnesses, as dummy cords to avoid losing small or important items, tying rucksacks to vehicle racks, securing camouflage nets to trees or vehicles, and so forth. When threaded with beads, paracord may be used as a pace counter to estimate ground covered by foot. The yarns of the core (commonly referred to as "the guts") can also be removed when finer string is needed, for instance as sewing thread to repair gear, or to be used as fishing line in a survival situation. The nylon sheath is often used alone, the yarn in the core removed, when a thinner or less elastic cord is needed such as when used as a boot lace. Ends of the cord are almost always melted and crimped to prevent fraying.
In addition to purely utility functions, paracord can be used to fashion knotted or braided bracelets, lanyards, belts, and other decorative items.
Types[edit]
US Military issue paracord is specified by MIL-C-5040H in six types: I, IA, II, IIA, III, IV.[2] Types IA and IIA are composed solely of a sheath without a core. Type III, a type commonly found in use, is nominally rated with a minimum breaking strength of 550 pounds, thus the sobriquet "550 cord".[citation needed]
The US military specification for paracord outlines a number of parameters to which the final product must conform. Although it contains specific denier figures for the sheath strands and inner yarns, there are no overall diameter requirements for the cord itself. Below is a table of selected elements from the specification.
| Type | Minimum strength | Minimum elongation | Minimum length per pound | Core yarns | Sheath structure |
|---|---|---|---|---|---|
| I | 100 lb (45 kg) | 30% | 950 ft (290 m; max. 1.57 g/m) | 1 | 16/1 |
| IA | ?95 lb (43 kg) | 30% | 1050 ft (320 m; max. 1.42 g/m) | <no core> | 16/1 |
| II | 400 lb (181 kg) | 30% | 265 ft (81 m; max. 5.62 g/m) | 4 to 7 | 32/1 or 36/1 |
| IIA | 225 lb (102 kg) | 30% | 495 ft (151 m; max. 3.00 g/m) | <no core> | 32/1 or 36/1 |
| III | 550 lb (249 kg) | 30% | 225 ft (69 m; max. 6.61 g/m) | 7 to 9 | 32/1 or 36/1 |
| IV | 750 lb (340 kg) | 30% | 165 ft (50 m; max. 9.02 g/m) | 11 | 32/1, 36/1, or 44/1 |
The Type III Specification is calculated using the value of 14.0625 feet per ounce.
A Core (also known as the Kern) is normally made up of two or three smaller nylon fibers twisted together.
Thickness- It should be noted that Mil-Spec Type III 550 version may be slightly thicker than commercial grade due to the Mil-Spec version often requiring 3 nylon fibers per inner core as opposed to the 2 nylon fibers per core of the Commercial version. Mil-Spec will be closer to a 4mm thickness, where Commercial versions are closer to a 3mm thickness. This will also vary if the Type III uses 7,8 or 9 inner cores. The most common on the commercial market is a 7 core.
Colors- It should be noted that there are only a handful of colors would meet Mil-Spec requirements. They are Black, Coyote Brown, Tan 499, Foliage Green, Olive Drab, Red (also known as Medic Red or Drab Red), Solar Orange (also known as Safety Orange or Drab Orange), Royal Blue, Silver, White and Natural (off-white). Any colors outside of this should be deemed as commercial grade and NOT Mil-Spec grade, unless the supplier can provide a valid Mil-Spec Certification Certificate to show otherwise. Unfortunately with the huge demand for paracord in the commercial market, many retailers believe it to be OK to say it is Mil-Spec since it was made on the same machine and using "some" of the same procedures.
Inner Core colors- In 2012-? some manufacturers began to place different color nylon cores into their cord. This was due to the lack of raw white inner core material being available (or so such has been stated). Prior to this if you saw an inner color core, one may have assumed it was Mil-Spec because such was required and may have not investigated further. It can now no longer be assumed, and one would need to look closer at the cord and request to see certification certificates if they are trying to source true Mil-Spec paracord.
Civilian availability[edit]
The same properties which soldiers appreciate in paracord are also useful in civilian applications. After World War II parachute cord became available to civilians, first as military surplus[3] and then as a common retail product from various surplus stores and websites. While some commercially available paracord is made to specification, even when labeled as such a given product may not correspond exactly to a specific military type and can be of differing construction, quality, color, or strength. Particularly poor quality examples may have significantly fewer strands in the sheath or core, cores constructed of bulk fiber rather than individual yarns, or include materials other than nylon.
Paracord has also been used by many since the 1970s for whipmaking. The durability and versatility of this material has proved beneficial for performing whip crackers and enthusiasts. Since nylon doesn't rot or mildew, it has become known as an all-weather material for whipmaking. Nylon whips have grown in popularity over the last few decades, more so in the last several years.[citation needed]
Hikers and other outdoor sports enthusiasts sometimes use "survival bracelets" made of several feet of paracord which is woven into a compact and wearable form. Such bracelets are meant to be unraveled when one needs rope for whatever purpose—securing cargo, lashing together poles, fixing broken straps or belts, assisting with water rescues, controlling bleeding with a tourniquet, etc.
Another use of parachute cord is in the stringing of mallet percussion instruments, such the xylophone, marimba, or vibraphone.
A very similar usage niche is nylon webbing, a strong, economical fabric woven as a flat strip or tube, also often used in place of rope.
Additional uses for parachute cord is in the manufacture of additional items, such as lanyards, belts, dog leashes, and key chains. This is becoming more popular as crafters are discovering this unique material.
References[edit]
- ^ Tom Nugent, "Blanketing the Hubble", University of Delaware Messenger, vol. 6, no.3 (1997)
- ^ MIL-C-5040H, Military Specification Cord, Fibrous, Nylon
- ^ Bill Ganze, "Surplus Everywhere", Farming in the 1940s
