3D Model — 2-Tonne Polyester Sling
Types of Synthetic Slings
Flat Webbing Slings
Woven polyester or nylon belt, typically 25–300mm wide. Available in single-ply or multi-ply. Most common type in Australian construction.
Round Slings (Endless)
Continuous loop of polyester yarns inside a protective tubular sleeve. Flexible, lightweight, and gentle on finished surfaces. Also colour-coded by WLL.
This Model
Shows a GREEN 2-tonne flat webbing sling with reinforced eyes. Green = 2t capacity per AS 1353.1 / AS 4497 colour coding.
Material Comparison
Polyester is the most common sling material in Australia. Nylon is used where elasticity or shock absorption is needed.
| Property | Polyester | Nylon |
|---|---|---|
| UV resistance | Good | Moderate |
| Stretch under load | Low (~3%) | High (~8%) |
| Max temperature | 100°C | 80°C |
| Shock load suitability | Fair | Good (absorbs energy) |
| Chemical resistance | Resistant to most, weak to alkalis | Resistant to most, damaged by acids |
| Water absorption | Minimal | Absorbs (can lose ~15% WLL when wet) |
| Prevalence in AU | Most common | Less common |
AS 1353.1 / AS 4497 Colour Coding
Synthetic slings are colour-coded by WLL so you can identify capacity at a glance. This is an Australian Standard requirement.
Exam tip: You MUST know the colour code. If a sling’s colour has faded beyond recognition, it must be removed from service — you cannot verify the WLL.
WLL by Hitch Method
The way you attach a sling to the load changes its effective WLL. These factors apply to the rated WLL on the tag.
| Hitch Method | Factor | Example (2t sling) |
|---|---|---|
| Vertical (straight) | 1.0× | 2,000 kg |
| Choker hitch | 0.8× | 1,600 kg |
| Basket hitch | 2.0× | 4,000 kg |
Basket Hitch Advantage
Both legs share the load equally • Only valid when legs are vertical
Choker Hitch Warning
- The choker hitch creates a pinch point that reduces capacity to 80%
- The sling must pull tight against the load — if it can slide, the load can shift
- Never choke a sling over a sharp edge without edge protection
Edge Protection
ALWAYS use edge protectors when a synthetic sling passes over a sharp corner or edge. Webbing cuts far more easily than wire rope or chain.
- Corner protectors (leather, rubber, or PVC sleeves) must be placed at every contact point with a sharp edge
- A “sharp edge” is any corner with a radius less than the sling thickness
- Steel beams, concrete panels, timber packs, and metal stillages all have edges that will cut webbing under load
- Minimum bend radius applies — slings must not be bent tighter than the manufacturer’s specification
- Even a small nick in the webbing concentrates stress and can cause the sling to fail under load
No Edge Protection = No Lift
- A 2-tonne sling can be cut in half by a steel edge in seconds under load
- If you cannot protect the edge, use chain slings or wire rope instead
- Assess EVERY lift for edge contact — it is the #1 cause of synthetic sling failure
Inspection & Rejection Criteria
Inspect synthetic slings before every use. Run the full length through your hands looking and feeling for damage.
Reject Immediately If
- Cuts or tears: any cut in the webbing, no matter how small
- Abrasion: surface fibres worn through exposing inner yarns
- UV damage: webbing is faded, stiff, or brittle (polyester becomes chalky)
- Chemical damage: discolouration, softening, or a chemical smell
- Heat damage: melted fibres, glazed surface, or stiffened areas
- Knots: NEVER tie a knot in a synthetic sling — reduces capacity by up to 50%
- Stretching: sling is visibly longer than its marked length
- Damaged eyes/fittings: stitching pulled, eyes distorted, or fittings cracked
- Missing or illegible tag: no identification = no use
Good Condition Indicators
- Webbing is supple, flexible, and uniform in colour
- No cuts, nicks, or frayed fibres visible
- Stitching intact at eyes and reinforcements
- Colour matches the rated WLL (not faded)
- ID tag legible with current test date
- No chemical odour or staining
Storage & Handling
- Store out of direct sunlight — UV degrades polyester and nylon over time, even when not in use
- Keep away from chemicals — acids destroy nylon, alkalis destroy polyester
- Hang on hooks or racks — never pile on the floor where they can be driven over, contaminated, or tangled
- Store in a dry, ventilated area — damp storage promotes mildew on nylon slings
- Do not store near heat sources — radiators, exhaust pipes, or welding areas
- Never drag slings across rough ground — abrasion damage is cumulative
- Do not use slings as tow ropes or tie-downs — they are lifting equipment only
- Tag and quarantine defective slings immediately — cut them if necessary to prevent reuse