Electric Hoist Wire Rope Selection Table (0.5t–20t)
When selecting or replacing an electric hoist wire rope, the biggest risk is choosing the wrong diameter or specification. This article provides a complete comparison table covering the full 0.5t–20t range—wire rope diameter, construction, pulley ratio, and minimum breaking force—and explains the safety factor calculation logic, construction implications, and drum matching rules behind the selection. By the end, you'll be able to look up the right rope on your own without flipping through multiple standard handbooks.
The wire rope on an electric hoist is one of the most critical load-bearing components of the entire machine, directly impacting lifting safety and equipment service life. Selection should never be based on hoist capacity alone—pulley ratio, wire rope construction, breaking force, and drum-and-sheave compatibility all come into play. Based on GB/T 8918-2006 Steel Wire Ropes for Important Purposes, ISO 4301 Crane Design Standard, and JB/T 9008.1-2014 Electric Hoists—Part 1: Types and Basic Parameters, this article compiles complete wire rope selection data for the full CD1/MD1 electric hoist range from 0.5t to 20t, with a point-by-point explanation of the selection basis.
CD1/MD1 Electric Hoist: Key Parameters at a Glance
Before diving into wire rope specifics, it helps to understand the lifting speeds and motor power ratings of the CD1/MD1 hoist series. Hoisting mechanisms vary by capacity, and these design differences directly influence wire rope load calculations.
| Specification(t) | Model | Lifting Speed(m/min) | motor power(k W) |
|---|---|---|---|
| 0.5 | CD1 0.5t | 8 | 0.8 |
| 1 | CD1 1t | 8 | 1.5 |
| 2 | CD1 2t | 8 | 3.0 |
| 3 | CD1 3t | 8 | 4.5 |
| 5 | CD1 5t | 8 | 7.5 |
| 10 | CD1 10t | 7 | 13 |
| 16 | CD1 16t | 3.5 | 18.5 |
| 20 | CD1 20t | 3.5 | 18.5 |
Note: For large tonnage hoists of 10t and above, a lower lifting speed (7m/min or 3.5m/min) is applied to improve control stability and safety during low-speed, heavy-load operations.
Electric Hoist Wire Rope Selection: Diameter & Breaking Force Table
The table below summarizes wire rope diameter, construction, pulley ratio, and minimum breaking force for electric hoists from 0.5t to 20t — your go-to reference for rope selection.
| Hoist Specification(t) | wire rope diameter(mm) | Wire rope construction | Pulley Ratio | minimum breaking force(k N) |
|---|---|---|---|---|
| 0.5 | 4.8~6.2 | 6×37+FC | 2/1 | ≥18 |
| 1 | 7.7~8 | 6×37+FC | 2 | ≥35 |
| 2 | 11~12 | 6×37+FC | 2 | ≥65 |
| 3 | 13~14 | 6×37+FC | 2 | ≥90 |
| 5 | 15~16 | 6×37+FC | 2 | ≥120 |
| 8* | 15~16 | 6×37+FC | 4 | ≥120 |
| 10 | 15~16 | 6×37+FC | 4 | ≥120 |
| 16 | 20~22 | 6×37+FC | 4 | ≥220 |
| 20 | 24~26 | 6×37+FC | 4 | ≥320 |
* 8t is a non-standard but commonly used specification, with the same wire rope configuration as the 10t model (different lifting capacities are achieved through pulley ratio variations).
Wire Rope Sizes for Electric Hoists by Capacity
Below are quick-reference answers for electric hoist wire rope diameters from 0.5t to 20t. Each question is presented as an independent entry for easy lookup:
What wire rope does a 0.5t electric hoist use?
A: The CD1 0.5t electric hoist uses a 4.8–6.2mm wire rope with a 6×37+FC construction, a 2/1 pulley ratio, and a minimum breaking force of ≥18kN.
What wire rope does a 1t electric hoist use?
A: The CD1 1t electric hoist uses a 7.7–8mm wire rope with a 6×37+FC construction, a pulley ratio of 2, and a minimum breaking force of ≥35kN.
What wire rope does a 2t electric hoist use?
A: The CD1 2t electric hoist uses an 11–12mm wire rope with a 6×37+FC construction, a pulley ratio of 2, and a minimum breaking force of ≥65kN.
What wire rope does a 3t electric hoist use?
A: The CD1 3t electric hoist uses a 13–14mm wire rope with a 6×37+FC construction, a pulley ratio of 2, and a minimum breaking force of ≥90kN.
What wire rope does a 5t electric hoist use?
A: The CD1 5t electric hoist uses a 15–16mm wire rope with a 6×37+FC construction, a pulley ratio of 2, and a minimum breaking force of ≥120kN.
What wire rope does an 8t electric hoist use?
A: The CD1 8t electric hoist uses a 15–16mm wire rope (same diameter as the 10t model, with different lifting capacities achieved through pulley ratio variations), a 6×37+FC construction, a pulley ratio of 4, and a minimum breaking force of ≥120kN.
What wire rope does a 10t electric hoist use?
A: The CD1 10t electric hoist uses a 15–16mm wire rope with a 6×37+FC construction, a pulley ratio of 4, and a minimum breaking force of ≥120kN.
What wire rope does a 16t electric hoist use?
A: The CD1 16t electric hoist uses a 20–22mm wire rope with a 6×37+FC construction, a pulley ratio of 4, and a minimum breaking force of ≥220kN.
What wire rope does a 20t electric hoist use?
A: The CD1 20t electric hoist uses a 24–26mm wire rope with a 6×37+FC construction, a pulley ratio of 4, and a minimum breaking force of ≥320kN.
Why This Diameter? The Safety Factor ≥5 Calculation
The wire rope diameter is determined primarily by the requirement of a safety factor ≥ 5 (per ISO 4301 Crane Design Standard, the wire rope safety factor for electric hoists in Work Duty classifications M3–M4 must not be less than 5). The calculation formula is:
Where the tension on a single rope = (Rated Load × Gravitational Acceleration g) ÷ Pulley Ratio.
Example: 5t electric hoist
Gravitational force: 5,000 × 9.8 = 49,000 N = 49 kN
Pulley ratio: 2 (load shared by two rope falls)
Tension per rope: 49 ÷ 2 = 24.5 kN
Minimum breaking force of wire rope (15–16mm): ≥120 kN
Actual safety factor: 120 ÷ 24.5 ≈ 4.9 ≈ 5
Example: 10t electric hoist
Gravity force: 10,000 × 9.8 = 98,000 N = 98 kN
Pulley ratio: 4 (load shared across four rope falls)
Force per rope fall: 98 ÷ 4 = 24.5 kN
Minimum breaking force of wire rope (15–16 mm): ≥120 kN
Actual safety factor: 120 ÷ 24.5 ≈ 4.9 ≈ 5
These two examples clearly illustrate the design rationale: although the 5t and 10t units differ in capacity, the maximum load on each individual wire rope is kept at approximately 24.5 kN — the 5t model achieves this with a pulley ratio of 2, while the 10t model uses a ratio of 4. This enables a common, standardized design for the wire rope and drum components. It's a classic normalization approach in engineering: using the same wire rope specification (15–16 mm) and simply adjusting the pulley ratio to cover different rated loads.
Wire Rope Construction Explained: What Does 6×37+FC Mean?
The comparison table lists the wire rope construction as 6×37+FC, an internationally recognized designation system for wire ropes. Here's what it breaks down to:
| Designation | Definition | Description |
|---|---|---|
| 6 | 6 Strand | Wire Rope Composed of 6 Strand Steel wire Wrapped aroundrope core Laid up |
| 37 | Each strand 37 Wires Steel wire | Each strand consists of 37 wires of varying diameters Steel wire Layered stranding(1+6+12+18 structure) |
| FC | Fiber corerope core(Fiber Core) | Made of natural or synthetic fiber, For lubricant retention Lubricationand support |
The total number of wires in the rope = 6 × 37 = 222. The 6×37+FC construction features a multi-wire line-contact structure, where the wires have large contact surfaces and evenly distributed stress, offering the following advantages:
- Excellent flexibility — Superior bending performance, well-suited for electric hoists with small-diameter drums in frequent hoisting and lowering cycles.
- Moderate wear resistance — Applicable to general industrial environments. For harsh conditions involving dust or moisture, 6×37+IWR (with an independent wire rope core) is recommended.
- Cost-effective — The FC rope core is 30%~40% less expensive than a metal core, making it the most widely adopted choice in the electric hoist industry.
What Is Pulley Ratio and How Does It Affect Wire Rope Selection?
Pulley ratio (also referred to as rope reeving ratio) is the number of rope branches that pass over the movable pulley in a hoisting mechanism — in other words, the number of wire rope lines carrying the load. A higher pulley ratio reduces the tension on each individual rope, allowing for a smaller wire rope diameter.
Typical pulley ratio configurations for electric hoists:
| Hoist Specification | Pulley Ratio | wire rope diameter | Load distribution logic |
|---|---|---|---|
| 0.5t | 2/1(Switchable) | 4.8~6.2mm | Single or double rope, Flexibility for low capacitiesconfiguration |
| 1t ~ 5t | 2 | 7.7~16mm | Dual-rope load sharing, Rope diameter Increasing with capacity |
| 8t ~ 20t | 4 | 15~26mm | Four-rope load sharing, Individual rope load control |
Key design insight: As the selection table above shows, the 5t (Pulley Ratio 2) and 10t (Pulley Ratio 4) hoists use the exact same wire rope diameter (15–16 mm) and breaking force (≥120 kN). This is because the 10t hoist has twice the pulley ratio of the 5t unit, so the load per rope remains essentially identical (24.5 kN each). This design approach effectively minimizes spare parts inventory—if a facility operates both 5t and 10t hoists, the wire rope can be shared across both.
Wire Rope Diameter vs. Drum and Sheave Sizing (D/d Ratio)
Selecting a wire rope based solely on breaking force is not sufficient—you must also match the drum and sheave diameters. ISO 4301 Crane Design Standard (ISO 4301) specifies the following minimum requirements:
Sheave diameter D₂ ≥ 20.0 × d (wire rope diameter)
The D/d ratio—the relationship between drum or sheave diameter and wire rope diameter—is a key parameter governing bending fatigue life. A lower ratio means tighter bending of the rope, which accelerates fatigue and shortens service life.
Minimum Drum and Sheave Diameters by Capacity
| Hoist Specification | wire rope diameter d | Drumminimum Diameter(22.4d) | Pulleyminimum Diameter(20d) |
|---|---|---|---|
| 0.5t | 5.5mm(Median value) | ≥124 mm | ≥110 mm |
| 1t | 8mm | ≥180 mm | ≥160 mm |
| 2t | 11.5mm | ≥258 mm | ≥230 mm |
| 3t | 13.5mm | ≥303 mm | ≥270 mm |
| 5t | 15.5mm | ≥348 mm | ≥310 mm |
| 10t | 15.5mm | ≥348 mm | ≥310 mm |
| 16t | 21mm | ≥471 mm | ≥420 mm |
| 20t | 25mm | ≥560 mm | ≥500 mm |
Why Is the D/d Ratio So Critical? Wire rope on an electric hoist is repeatedly wound onto and off the drum and bent around pulleys. The smaller the D/d ratio, the greater the inter-strand slippage and compressive stress—factors that directly determine wire rope service life. Field data shows that when D/d drops from 25 to 20, bending fatigue life decreases by roughly 30%–40%. For this reason, never sacrifice the D/d ratio to reduce drum dimensions.
Related Standards at a Glance
Electric hoist wire rope selection is governed by the following national standards. Reference them during procurement and acceptance:
- GB/T 8918-2006 Steel wire ropes for important purposes—Specifies technical requirements, test methods, and acceptance standards.
- GB/T 5972-2016 Cranes—Wire ropes—Care, maintenance, inspection, and discard—Provides guidance on daily inspection, lubrication, and discard criteria.
- ISO 4301 Crane design specification—Requires drum D≥22.4d, pulley D≥20d, and minimum safety factors.
- JB/T 9008.1-2014 Electric hoists—Part 1: Types and basic parameters—Industry standard covering hoist overall parameters.
Selection Recommendations: Key Takeaways
Electric Hoist Wire Rope Selection Key Points
- Use the lookup table first—Match hoist capacity and pulley ratio directly to the comparison table in this article. Data covers the full 0.5t–20t range, so no manual calculation is needed.
- Safety factor ≥5 is the minimum—After selection, always verify that single-rope tension ÷ breaking force ≥ 5. Do not downgrade to a lower spec to save cost.
- Standardize on 6×37+FC construction—This is the universal choice across the range. The FC fiber core offers good flexibility and cost-effectiveness; switch to an IWR metal core in harsh environments.
- Pulley ratio determines per-rope load—For large tonnage, increase the pulley ratio rather than rope diameter to share the load. This is standard design practice.
- Never compress the D/d ratio—Drum D≥22.4d and pulley D≥20d. Reducing these saves space but significantly shortens service life.
- Follow national standards for daily inspection—Perform a visual inspection monthly, measure diameter quarterly, and discard immediately if broken wires exceed 10%. Safety comes first.
— End of Article —
Data in this article is compiled per GB/T 8918-2006, ISO 4301, GB/T 5972-2016, and JB/T 9008.1-2014 for technical selection reference.
FAQ
Q: How often should electric hoist wire rope be replaced?
A: There is no fixed replacement interval—it depends on usage frequency, load factor, and operating conditions. Per GB/T 5972-2016, the rope must be scrapped and replaced when the number of broken wires within one lay length reaches 10% of the total wire count, when diameter wear exceeds 7%, or when kinking or severe corrosion is present. A visual inspection is recommended monthly, with a diameter measurement quarterly.
Q: Can I use a thicker wire rope as a replacement?
A: Upsizing the rope diameter on your own is not recommended. A larger rope reduces the D/d ratio on the drum and pulleys, which actually accelerates fatigue damage. In addition, a thicker rope may exceed the drum groove capacity, causing poor spooling and crushing deformation. To improve the safety factor, adjust the pulley ratio or switch to a rope with a higher breaking force rating—not simply increase the diameter.
Q: What is the difference between 6×37+FC and 6×19+FC?
A: 6×37+FC has 37 wires per strand in a multi-wire, fine-wire construction, offering better flexibility for small-diameter drums. 6×19+FC has 19 thicker wires per strand, providing better wear resistance but poorer bending performance. Because electric hoist drums are relatively small in diameter, 6×37+FC is the standard choice across the board.
Q: Can wire rope with visible broken wires still be used?
A: It depends on the number and location of the broken wires. Per GB/T 5972-2016, the rope must be discarded when broken wires within one lay length (approximately 6.5 times the rope diameter) exceed 10% of the total wire count. For example, a 15 mm diameter 6×37+FC rope has 222 wires total—if more than 22 wires are broken within one lay length, the rope must be replaced. Broken wires concentrated in a single strand or near the end fitting are more dangerous, and replacement is recommended even if only a few are present.
