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Wire Rope Construction Guide
What the numbers mean, how the common constructions behave, and which one fits the job.
Reading a Wire Rope Name
A construction name such as 6x19 packs two facts: the number of strands, and the wires in each strand. 6x19 is six strands of nineteen wires, laid around a core. More and thinner wires make a rope more flexible; fewer, thicker wires make it stiffer and more abrasion resistant.
Two further choices sit behind the name. The core can be fiber or an independent wire rope core, which changes strength and crush resistance - the core types guide covers the difference.
And the finish is bright or galvanized, which decides how the rope stands up outdoors - see the galvanized wire rope guide.
How the Common Constructions Behave
| Construction | Character | Where it fits |
|---|---|---|
| 1x19 | 19 wires in a single strand; the stiffest common rope, with high breaking strength and low stretch | Structural stays, guardrails and rigging where stretch must stay low |
| 7x7 | Seven strands of seven wires; available in small diameters from 0.5 mm; stiffens above about 6 mm | Small control cables, lanyards and light rigging |
| 6x19 | Six strands of nineteen wires; filler (12/6+6F/1) and sealed (9/9/1) variants; the long-standing general-purpose rope | General engineering, hoisting and guy lines |
| 7x19 | Seven strands of nineteen wires; the most flexible of the common constructions | Pulleys, small sheaves, winching and pulling lines |
| 6x36 | Six strands of thirty-six wires (14/7+7/7/1); flexible and resistant to bending fatigue | Crane hoisting, grab lines and winch ropes |
| Rotation-resistant | 18x7, 19x7, 32x7 and 35x7; layers of strands laid in opposite directions, so the rope does not spin under load | Single-line lifting where the load must not turn: tower cranes, offshore and hoist duty |
| Compacted | Outer strands compacted before closing; smoother, wear-resistant surface and higher breaking strength | Service where abrasion and strength both matter |
| Coated | A PVC or PE jacket over the rope | Protection and handling in outdoor, marine and recreation use |
All constructions are made to GB/T 20118-2006 and supplied bright or galvanized.
Choosing by Application
- Structural stays and guardrails: 1x19 for high strength and low stretch.
- Pulleys, blocks and pulling lines: 7x19 for maximum flexibility.
- General hoisting and guy lines: 6x19, the all-round choice.
- Crane hoisting, grabs and winches: 6x36 for bending fatigue resistance.
- Single-line lifting where the load must not turn: 18x7, 19x7, 32x7 or 35x7 rotation-resistant ropes.
- Small-diameter control and light rigging: 7x7.
- Outdoor, wet or marine service: galvanized finish.
Fittings are available to finish the assembly: thimble eyes, swaged terminals and wedge sockets. Tell us the load, the sheave or drum it runs on and the environment, and we will match the construction, core and finish.
Our Wire Rope Range
Greenlogy TEC supplies multi-strand bright or galvanized wire rope in diameters from 0.5 mm to 64 mm, with fiber core and steel core options. Common constructions in the range: 1x19,
7x19, 6x36 FC and 6x36 IWRC, and rotation-resistant 19x7 and 32x7.
Compare the fiber and steel core versions in the core types guide, check lifting capacities in the breaking strength guide, or browse the full wire rope range.
Send your duty to admin@greenlogy.cn for a construction recommendation.
Strands, wires and how a designation is written
A construction name is shorthand, and the shorthand hides the layer that decides how the rope behaves. Wires are twisted into a strand, strands are laid helically around a core, and the whole is closed into a rope. 6x19 names the first two layers - six strands, nineteen wires in each - while the core is stated separately, as FC or IWRC.
The pattern of the wires inside the strand is written after the count, because nineteen wires can be arranged in more than one way and the arrangement, not the count, sets how the strand bends and wears. Two patterns are in production under 6x19. Sealed is written 9/9/1: nine wires closing over nine, around a single centre wire. Filler is written 12/6+6F/1: twelve wires over six, with six filler wires seated in the gaps and one centre wire. A slash separates layers, an F marks a filler wire, and the trailing 1 is the centre.
6x36 is written 14/7+7/7/1 - fourteen wires in the outer layer, seven beneath them, then two further seven-wire layers over the centre. Four thinner layers put more wire on the strand surface and leave more room to bend than a nineteen-wire strand of the same diameter, which is why the rope tolerates smaller sheaves and repeated bending.
The core is the third layer, and it is not decoration. A fiber core cushions the strands and keeps the rope flexible; an independent wire rope core resists crushing and adds strength at the same outside diameter. The core types guide compares the two in detail.
Same diameter, a different rope
Fix the diameter and look only at the pattern, and the difference is immediate. The rows below are all 10 mm, taken from the published product tables:
| Construction | Grade | MBL (kN) | What the pattern does |
|---|---|---|---|
| 1x19 | 1770 MPa | 92.9 | One solid strand: the most metal in the section, the highest breaking load |
| 6x36 IWRC | 1770 MPa | 63.0 | Many thin wires - it bends, at a lower breaking load than a solid strand |
| 6x7 | 1770 MPa | 58.8 | Few, thick wires - abrasion resistant, below the fine-wire constructions |
| 7x19 | 1570 MPa | 55.6 | The most flexible; this row is also a 1570 grade, so part of the gap is grade |
Part of the 7x19 figure comes from its lower grade, not only from its pattern - read the two together. Full tables by diameter are in the breaking strength guide.
The pattern is not cosmetic: at 10 mm the stiffest construction carries about two-thirds more breaking load than the most flexible one. That is why a rope is chosen against both duties at once - the load it must hold and the sheave it must bend over - and not by diameter alone.
Lay: what the name 6x19 does not tell you
Two ropes can both be 6x19 IWRC at 1770 MPa and still behave differently, because the lay is a separate decision. The lay is the helical pitch of the strands: it has a direction, right-hand or left-hand, and a length - the distance one strand travels in a complete turn.
In regular lay the wires inside each strand run in the opposite direction to the strands themselves. That counter-balance stops the rope untwisting under load, and makes regular lay the general-purpose choice. In lang lay the wires follow the strand direction instead: the rope bends more easily and puts more wire on the wearing surface, but it rotates more readily under a single-line load, so it is used where both ends are fixed against turning.
Lay length is the other half of the decision. A short lay, with more turns per metre, makes the rope more flexible and puts more wire where it wears, at some cost in breaking strength. A long lay is stiffer and stronger in a straight pull. When you re-rope an existing machine, take the hand and the lay from the manual or from the old rope: a left-hand rope will not spool the way its right-hand twin does.
Rotation is the one consequence that changes the construction rather than the lay. A single-layer rope turns under load; a rope built from strand layers laid in opposite directions cancels the turning force. The rotation-resistant wire rope guide covers that family - the lay is the mechanism behind it.
Choosing a construction by what the rope must survive
Application decides more than preference. Where two duties pull in opposite directions - abrasion wants fewer, thicker wires, bending fatigue wants more, thinner ones - the sheave or drum usually settles it, because a rope that cannot bend fails early no matter how well it wears.
| Duty or problem | What changes in the rope | Constructions in this range |
|---|---|---|
| Single-line lift that must not turn | Strand layers laid in opposite directions | 18x7, 19x7, 32x7, 35x7 |
| Small sheave, tight drum, repeated bending | More and thinner wires per strand | 7x19, 6x36 |
| Abrasion from dragging or reverse bends | Fewer, thicker outer wires; compacted strands | 6x19, compacted versions |
| Structural stay or guy needing low stretch | A single-strand rope | 1x19 |
| Diameters below about 6 mm | Few wires, small strands | 7x7 |
| Crushing on multilayer spooling | An independent wire rope core | IWRC versions |
| Wet, outdoor or marine service | Zinc coating on the wires | Galvanized |
| Higher strength at the same diameter | Compacted strands, or a higher grade | Compacted; 1770 / 1960 MPa |
This table picks the pattern, not the size. Published breaking loads for each construction and diameter are in the breaking strength guide.
Specifying a rope in one enquiry
A construction name starts the conversation; a quotable specification has eight parts. Give as many as you know and we will confirm the rest against the duty.
- Construction and pattern - 6x19 sealed (9/9/1), 6x19 filler (12/6+6F/1), 6x36 (14/7+7/7/1), 7x19, 1x19 or a rotation-resistant rope
- Diameter, in millimetres or inches
- Core - fiber (FC) or independent wire rope core (IWRC)
- Grade - 1570, 1770 or 1960 MPa
- Lay, if the machine specifies a hand or a lay length
- Finish - bright, galvanized, or PVC / PE coated
- Termination - thimble eye, swaged terminal, wedge socket or plain ends
- Duty - the load, the sheave or drum diameter, the environment, and the length per reel
Each choice has its own guide: core types guide, galvanized wire rope guide, stainless steel wire rope guide and rotation-resistant wire rope guide. Compare examples across the wire rope range, size a lift with the breaking strength guide, or use the wire rope selector if you would rather answer questions than read tables.
Send the eight points to admin@greenlogy.cn and we will return a construction, a core and a finish, with the published breaking load for the diameter you need.
Frequently Asked Questions
What does 6x19 wire rope mean?
It is six strands, each built from nineteen wires, laid around a core. The first number is the strand count and the second is the wires per strand. Generally, the more and thinner the wires, the more flexible the rope.
What is the difference between 6x19 and 6x36 wire rope?
6x19 has six strands of nineteen wires and is a long-standing general-purpose rope. 6x36 has six strands of thirty-six thinner wires, making it more flexible and more resistant to bending fatigue, which suits crane hoisting and winch duty.
Which wire rope construction is the most flexible?
Among the common constructions, 7x19 is the most flexible and is used over pulleys and for pulling lines. 6x36 is close behind for lifting duty. 1x19 is the stiffest, with the lowest stretch.
What is a rotation-resistant wire rope?
A rope built from multiple layers of strands laid in opposite directions, such as 18x7, 19x7, 32x7 and 35x7. The opposing lays cancel the turning force, so a single-line lift does not spin the load.
What standard are your wire ropes made to?
Our wire ropes are made to GB/T 20118-2006 and supplied bright or galvanized, in diameters from 0.5 mm to 64 mm.