Round Sling Width Size Analysis: International Standard and Made in China

Round Sling is a central tool in industrial lifting, its color and width are not only a visual indication of load capacity, but also a key basis for safe operation. According to international standards (e.g. EN 1492-1, ISO 9001), slings with different safety factors (4:1, 5:1, 6:1) need to be clearly distinguished by color and size.

Safety Factor and Width Calculation Formula

1. Meaning of Safety Factor

Lifting sling safety factor is the ratio of the breaking load (BLL) to the working load (WLL) of the sling, the formula is:

Safety Factor = Breaking Load (BLL) / Working Load (WLL)

2.Factor of safety Scenarios

4:1 Conventional industrial lifting (e.g. equipment handling, warehousing and logistics)

5:1 High-risk environments (e.g. construction sites, marine operations)

6:1 Extremely heavy loads or dynamic lifting (e.g. wind turbine installation)

3. Width calculation formula

According to international standards, the width of sling is designed according to the following rules:

1 Ton (T): Base width is 30mm.

2T and above: width = tonnage × 25mm (e.g. 2T = 50mm, 3T = 75mm, and so on).

Polyester Round Sling color and width comparison table

The following are specifications for 4:1, 5:1 and 6:1 safety factor slings made in China, compatible with EN 1492-1 standard:

Working Load (WLL) Color Width (single layer) Description of multi-layer construction

1T Purple 30mm Single woven

2T Green 50mm (2 x 25mm) Single layer

3T Yellow 75mm (3 x 25mm) Single layer

4T Gray 100mm (4×25mm) Single Layer

5T Red 125mm (5 x 25mm) Single Layer

6T Brown 150mm (6×25mm) Single Level

8T Blue 200mm (8×25mm) Single Level

10T Orange 250mm (10×25mm) Single Level

12T Orange 300mm (12×25mm) Single layer

15T Blue 200mm (8 x 25mm) Four-ply stacked structure, total width 200mm x 4 ply

20T Orange 250mm (10 x 25mm) 4-ply stacked structure, total width 250mm x 4 ply

25T Orange 300mm (12×25mm) four-layer stacked structure, total width 300mm×4 layers

Note: Multi-layer slings enhance strength by increasing the number of woven layers, rather than simply widening the size of a single layer.

Compatibility between international standards and Made-in-China

1. Global uniformity of color and width

EN 1492-1: EU standard requires strict correspondence between color and tonnage, and China manufacturing standard is fully compatible with it.

ASME B30.9: American standard allows flexible color matching, but Chinese export products usually follow EN norms to meet global sourcing requirements.

2. Technical advantages of multi-layer structure

High Strength: The four-ply weave design increases the breaking load of 15T-25T slings up to four times that of a single ply at the same width.

Durability: Multi-layer fiber disperses stress and reduces local wear and tear, extending the life span by 50%.

Selection guide and use specification

1. Selection steps

Determine the load demand: Select WLL (working load) according to the actual lifting weight.

Match the safety factor: choose 6:1 for high-risk scenarios and 4:1 or 5:1 for regular work.

Check the color and width: Quickly identify the tonnage by color and verify whether the width meets the 25mm times rule.

2. Precautions for use

Prohibit overloading: even short-term overloading may cause internal fiber breakage.

3.Environmental suitability:

Humid environment: choose the model with anti-mold coating.

High-temperature scenario: Temperature resistance range should be ≥120℃ (e.g. aramid fiber material).

Regular testing: breakage test every 6 months, mandatory replacement when the load is less than 80% of the nominal value.

V. Competitive Advantages of Made in China

1. Quality control of the whole industrial chain

Raw material: 100% polyester fiber from Yizheng Chemical Fiber and other domestic first-class suppliers, with tensile strength ≥8000N/mm².

Production process: fully automatic knitting machine ensures the error ≤±1%, and the hot press stitching technology improves the seam strength by 30%.

2. Customized service

Non-standard design: support special color, LOGO printing and length customization (1-30m).

Fast delivery: sufficient stock of standard models, delivery cycle of customized products above 15T ≤ 7 days.