Nylon, Polyester and UHMWPE: Rope Materials Explained
Nylon, polyester and UHMWPE each do a different job aboard. Here's the plain-English version.
| Nylon | Stretches the most. Good where shock absorption matters: dock lines, anchor rodes and snubbers. Loses some strength when wet and can harden with age and UV. |
|---|---|
| Polyester | Moderate stretch, good UV and abrasion resistance. Common for sheets, halyards and general running rigging. |
| UHMWPE (ultra-high-molecular-weight polyethylene) | Very low stretch and very light for its size; floats. Used for soft shackles, lashings and performance running rigging. Slippery, so knots hold poorly; it creeps under sustained load and is weakened by heat. Sold under several fiber brand names; ours is a generic UHMWPE fiber and we don't use brand names we can't document. |
Construction
- Three-strand: laid rope; easy to splice, stretchy, can kink.
- Double braid: core plus cover; smooth, strong, kink-resistant.
- 12-strand single braid: one hollow braid, common for UHMWPE; easy to splice with a fid.
About strength numbers
"Breaking strength" is the load at which a new sample broke in a test, usually in a straight pull with spliced ends. Knots, sharp bends, chafe, age and UV all reduce it, often a lot. A safe working load is a much smaller fraction set for a specific use. We don't publish working loads, and we label every strength number with its source.