Lifting Slings Buying Guide: Key Factors for Your Facility

A facility manager needs to replace a worn-out set of lifting slings. The purchase order is straightforward: “4-ton web slings, 6-foot length, 4 each.” But when the slings arrive, the rigging crew discovers they are nylon—and the facility’s lifting area has consistent exposure to acidic fumes from a nearby plating line. The slings degrade within weeks, creating a safety hazard and a costly re-order.

This scenario illustrates a fundamental truth: buying lifting slings requires more than specifying a capacity. Lishenflex has been manufacturing synthetic lifting slings for decades, and our experience with facility procurement teams shows that the most successful purchases are guided by a structured evaluation of five key factors.

1. Material Selection: Match the Sling to the Environment

The first decision is material. Synthetic lifting slings are made from polyester (PES) , polyamide (nylon, PA) , or polypropylene (PP) . Each material has distinct chemical and temperature profiles.

Per EN 1492-1, polyester and polyamide slings are suitable for use and storage in temperatures from -40°C to 100°C, while polypropylene slings are rated for -40°C to 80°C .

The chemical resistance difference is critical:

Source: CCOHS; EN 1492-1

Lishenflex’s field data show that material mismatch is the single most common cause of premature sling failure in chemically active facilities. If your lifting area has acid exposure—plating lines, battery rooms, chemical processing—specify polyester. If alkali exposure is present—concrete, caustic cleaning—specify nylon.

2. Configuration: Eye & Eye, Endless, or Round

Synthetic slings come in several configurations, each suited to different lifting tasks.

Flat webbing slings are available as eye & eye (Type 3 or Type 4) or endless (Type 5) . Eye & eye slings offer fast attachment and are ideal for standardized lifts. Endless slings can be rotated to distribute wear, extending service life.

Round slings (covered endless slings) offer superior load protection and are preferred for irregular or delicate loads. According to AS 4497:2018, round slings must have a minimum breaking load of seven times their working load limit and be proof loaded to two times their WLL .

For multi-leg lifts, bridle slings with master links simplify attachment to crane hooks.

3. Capacity and Safety Factor

The working load limit (WLL) must equal or exceed the heaviest load in your facility, with margin for angle factors and hitch configurations.

Synthetic slings are rated with a 7:1 safety factor under EN 1492-1 and EN 1492-2 . This means a sling with a 2-ton WLL has a minimum breaking strength of 14 tons.

Critical consideration: The WLL marked on the tag assumes a vertical, straight lift. When slings are used in choker hitches, capacity is reduced by 20%. In basket hitches, capacity increases depending on the angle .

4. Standards Compliance

Purchasing slings that meet recognized standards is not optional—it is the foundation of legal compliance and workplace safety.

OSHA 1910.184 and ASME B30.9 are the primary standards for sling selection, inspection, and use in the United States . EN 1492-1 and EN 1492-2 apply in Europe .

Per ASME B30.9, each sling must be permanently marked with:

• Manufacturer’s name or trademark

• Manufacturer’s code or stock number

• Rated load for at least one hitch type

• Type of synthetic material

• Number of legs (if more than one)

Missing or illegible identification is a removal criterion—a sling without legible markings cannot legally be used .

5. Inspection and Documentation Requirements

Buying slings is only the beginning. OSHA and ASME B30.9 require a layered inspection program:

OSHA requires that employers maintain a record of the most recent periodic inspection . Failure to maintain records is one of the most common compliance gaps identified during inspections.

Lishenflex manufactures polyester and nylon lifting slings to EN 1492-1 and ASME B30.9 standards, with clear color-coded capacity markings, permanent identification tags, and material options for acid or alkali environments. Our products are available in flat webbing (eye & eye and endless) and round sling configurations.

If you need assistance selecting the right lifting slings for your facility—or need help evaluating your current sling inventory against OSHA and ASME B30.9 requirements—please send an email to sales@lishenflex.com, and our technical team will provide one-on-one support.