8×31WS Line Contact Wire Rope

8×31WS Line Contact Wire Rope Sizes:

8×31WS Line Contact Wire Rope Sizes

Nominal Diameter	Weight (kg/100m)			Nominal Tensile Strength of Rope (MPA)
				1570		1670		1770		1870		1960
				Minimum Breaking Load of Rope (kn)
(mm)	NF	SF	IWR/IWS	FC	IWR/IWS	FC	IWR/IWS	FC	IWR/IWS	FC	IWR/IWS	FC	IWR/IWS
8	22.98	22	27.9	29.3	34.7	31.2	36.9	33.1	39.1	35	41.3	36.7	43.4
9	29	27.8	35.3	37.1	43.9	39.5	46.7	41.9	49.5	44.3	52.3	46.5	54.9
10	35.9	34.4	43.6	45.8	54.2	48.8	57.6	51.7	61.1	54.7	64.6	57.4	67.8
11	43.3	42.6	52.7	55.5	65.5	59	69.7	62.6	73.9	66.2	78.2	69.5	82
12	51.5	49.5	62.8	66	78	70.2	83	74.5	88	78.7	93	82.7	97.6
13	60.4	58.1	73.6	77.5	91.5	82.5	97.4	87.4	103	92.4	109	97	114
14	70.1	67.4	85.4	89.8	106	95.6	113	101	120	107	127	112	133
16	91.6	88	111	117	139	125	148	132	156	140	165	147	173
18	116	111	141	149	176	158	187	168	198	177	209	186	220
20	143	138	174	184	217	195	231	207	224	219	258	230	271
22	173	166	210	222	262	236	279	250	296	265	313	278	328
24	206	198	251	264	312	281	332	298	352	315	372	330	390
26	242	232	295	310	367	330	390	350	413	370	437	388	458
28	280	270	342	360	425	384	453	406	480	429	507	450	531
30	322	310	392	414	488	440	520	446	551	493	582	516	610
32	366	352	446	471	556	501	591	531	627	561	662	588	694
34	414	398	504	532	628	565	668	600	707	633	747	663	784
36	464	446	565	596	704	634	748	672	793	710	838	744	878
38	517	497	630	664	784	706	834	748	884	791	934	829	979
40	572	550	698	736	869	782	924	830	979	876	1035	918	1085
42	631	607	769	811	958	863	1019	914	1080	966	1141	1013	1196
44	693	666	844	890	1051	947	1118	1004	1185	1060	1252	111	1312
46	757	730	922	973	1140	1035	1222	1090	1295	1150	1360	1215	1434
48	825	793	1004	1050	1251	1120	1331	1194	1411	1262	1490	1323	1562
50	895	860	1090	1150	1358	1223	1444	1296	1531	1369	1617	1435	1695
52	968	930	1179	1243	1468	1323	1562	1402	1655	1481	1749	1552	1833
54	1044	1003	1271	1341	1584	1426	1684	1512	1785	1597	1886	1674	1977
56	1122	1079	1367	1442	1703	1534	1812	1626	1920	1718	2029	1800	2126
58	1204	1157	1466	1547	1827	1646	1943	1744	2060	1843	2176	1931	2281
60	1288	1238	1570	1656	1955	1761	2080	1866	2204	1972	2329	2067	2441

What Is an 8x31WS Line Contact Wire Rope and Why Should You Care?

An 8x31WS wire rope is a specialized steel cable with 8 strands, each containing 31 wires. The “WS” (Warrington Seale) design provides line contact between wires. This offers excellent flexibility, fatigue resistance, and crush resistance, making it ideal for demanding lifting applications.

I remember talking to Mark, a long-time customer from the US. He runs a successful distribution business. He once bought a batch of standard wire rope from another supplier for a big crane contract. The ropes failed inspection after only a few months because of severe internal wear and crushing on the drum. He lost time and money. After that experience, he called me to understand why not all wire ropes are created equal. It’s not just about the price tag; it’s about understanding the construction. Let’s break down what makes the 8x31WS, a specific rope type, a superior choice for many jobs.

What Do the Numbers “8×31” Actually Mean?

“8×31” describes the rope’s construction. It has 8 outer strands wrapped around a core. Each of those strands consists of 31 individual wires. This high-wire count gives it great flexibility and fatigue resistance, vital for many lifting operations.

Let’s look closer at these numbers. The first number, “8,” tells you how many strands are wrapped around the rope’s central core. The most common wire ropes you see are 6-strand. Using 8 strands makes the rope more flexible and rounder. This helps it run smoothly over sheaves and pulleys.

The second number, “31,” indicates the number of individual wires in each of those 8 strands. A higher wire count, like 31, means the individual wires are smaller. This dramatically increases the rope’s flexibility and its ability to resist fatigue from bending back and forth. It’s a simple trade-off. Fewer, larger wires offer more abrasion resistance. More, smaller wires offer better flexibility and fatigue life.

Feature Comparison	8x31WS	6×19 Class	6×37 Class
Flexibility	Excellent	Good	Very Good
Fatigue Resistance	Excellent	Good	Very Good
Abrasion Resistance	Good	Very Good	Good
Common Use	Crane Hoists, Winches	General Purpose, Stays	Cranes, Hoists

For a business owner like Mark, choosing 8×31 means investing in a rope that will last longer in high-cycle lifting jobs. This reduces downtime and replacement costs.

Why is the “WS” (Warrington Seale) Construction So Important?

“WS” stands for Warrington Seale. It’s a special wire arrangement within each strand. It creates “line contact” between wire layers, not just “point contact.” This reduces internal wear, increasing the rope’s lifespan and fatigue resistance.

This is where the real engineering magic happens. Inside each strand of a wire rope, there are multiple layers of wires. How these wires touch each other determines the rope’s performance and lifespan.

Understanding Point Contact

In many standard rope designs, the wires in different layers are not arranged in parallel. When the rope bends or is loaded, the wires cross over each other. They touch at very small points. All the pressure is concentrated on these tiny points. This creates high stress, internal friction, and “nicking,” leading to premature wire breaks within the rope. You might not even see the damage until it’s too late.

The Advantage of Line Contact

The Warrington Seale (WS) construction is much smarter. It uses a combination of different wire sizes in the layers of each strand. The outer layer has large wires for abrasion resistance (Seale). An inner layer has alternating large and small wires (Warrington). This design ensures that the wires in each layer sit snugly in the valleys of the layer below. Instead of a single point of contact, they touch along a continuous line. This spreads the load and pressure over a much larger area, significantly reducing internal stress and friction. This is why WS ropes have superior fatigue resistance. They can bend and flex for many more cycles before they begin to fail.

What are the Best Applications for 8x31WS Wire Rope?

8x31WS wire rope excels in applications needing high flexibility and resistance to crushing and fatigue. This makes it ideal for crane hoist ropes, winch lines, and other equipment that run over sheaves and drums under heavy loads.

The unique combination of flexibility, fatigue resistance, and crush resistance makes 8x31WS the premium choice for specific, heavy-duty jobs. If your rope is constantly bending over sheaves or getting wound tightly onto a multi-layer drum, this is the rope you should be considering. Its 8-strand line-contact design helps it resist distortion and internal damage in these tough conditions. For procurement officers, specifying this rope for the right application means fewer breakdowns, safer operations, and a better return on investment. It might have a higher initial cost than a 6×19 rope, but its extended service life often makes it the more economical choice in the long run.

Application	Why 8x31WS is a Good Fit
Main Crane Hoist Lines	Superior fatigue resistance withstands constant bending over sheaves, increasing service life and safety.
Winch Ropes	Excellent crush resistance prevents flattening and damage when spooled onto a drum under tension.
Overhead Cranes	High flexibility and long life reduce the frequency of costly rope changes and operational downtime.
Drilling Rigs	The robust construction can withstand dynamic loads and harsh environments encountered in drilling operations.

How Do You Inspect and Maintain 8x31WS Wire Rope?

Regularly inspect for broken wires, corrosion, abrasion, and signs of crushing. Follow a consistent lubrication schedule. Proper inspection and maintenance are crucial for safety and extending the service life of your 8x31WS rope.

Even the highest quality rope needs proper care. As a manufacturer, I can’t stress this enough. When I sell ropes to customers like Mark, I always emphasize that the partnership doesn’t end with the sale. Ensuring the product is used safely and lasts as long as possible is key. A cheap rope from an unreliable supplier won’t come with this support.

Visual Inspection Checklist

You or your trained personnel should regularly walk the length of the rope and look for problems. Keep an eye out for clusters of broken wires, signs of the rope being crushed or flattened, and any “bird caging” where strands have opened up. These are all signs that the rope may need to be retired from service.

The Importance of Lubrication

A wire rope is a machine with many moving parts. Those 248 wires (8 strands x 31 wires) move against each other every time the rope bends. Lubrication is critical. It reduces internal friction, thereby improving fatigue life. It also provides a protective barrier against moisture and corrosion. A proper lubrication program can easily double the effective life of your rope.