Keep in mind for safety reasons that the size (diameter) of the rope isn’t the best indicator of its strength. Actually, the rope material has a great impact on its strength. Always read the strength specification shown on the package for the maximum weight it can handle. Don’t compromise to get something cheaper.
As you probably found, most rope you find at hardware and home-center stores is made of three-strand twisted yellow plastic. The type of plastic is actually polypropylene. It’s inexpensive, but it’s really not the best type of rope for most applications.
Three important factors to consider when selecting the proper type of rope for a job are relative strength, elasticity, and knot-forming characteristics. No one type of rope is best in all these factors, so it’s best to have several types of rope on hand.
Yellow polypropylene rope has medium strength and low elasticity. This makes it fine for holding light loads. It’s made of plastic, so it isn’t harmed by moisture and can be stored anywhere without concern for rot. It’s commonly used on boats and around swimming pools because it’s the only common type of rope that floats on water.
One drawback of polypropylene rope is it’s stiff and difficult to tie into a knot. Polypropylene plastic is often used for living hinges in plastic items, so it has a memory. If you try to tie it into a knot, it usually springs back and unties itself. When polypropylene rope gets old, it has an unpleasant prickly feel when handling it.
White polyester rope is better to use for supporting items because it’s relatively strong and has very low elasticity. The combination of its stiffness and strength makes it particularly good when lifting heavy items. It costs slightly more than $1 per foot for typical 5/8-inch-diameter rope.
If you have to make knots with polyester rope to tie something down, select a soft-laid type of rope, which is more flexible. For straight lifting and strength, a hard-laid type is best. Being made of plastic, it’s rot-resistant and can be stored and used in damp locations.
Nylon rope costs about the same and has similar properties to polyester rope. The major difference is nylon rope is much more elastic. This makes it less applicable to lifting and tying heavy loads but much better for a safety rope. If you fall and are supported by nylon rope, its elasticity will ease and absorb some of the shock. This is also a benefit when pulling out a car that is stuck in mud.
The other two less expensive types of rope are made from natural materials. Manila rope is moderately strong and good for pulley applications because it doesn’t stretch much and is stiff. It’s often coated with oil so it resists rot. Natural sisal fiber rope is the most inexpensive, and it’s a good general-purpose rope for packaging and bundling yard waste. It isn’t oil-coated, so it can go in the compost pile.
