Check-Fast® Inspection System

US Patent #7,661,737 CA #2,547,632 EP #1,899,255

The Check-Fast® Inspection System is designed to improve job site safety. The Check-Fast® External Warning Indicator (EWI) provides a criteria for pass/fail inspection when the internal load-bearing core yarn may be damaged. The Check- Fast® Inspection System can also indicate ultraviolet (UV) light degradation, fiber-on-fiber abrasion, fatigue, and severe overload. If the sling is overloaded beyond its rated capacity, the EWI is designed to retract before the sling fails. The sling inspector now has an objective “GO/NO-GO” inspection device rather than relying on subjective and laborintensive inspection techniques to guess if the load-bearing core yarns are in good condition.

Fiber Optic Inspection

Fiber Optic Inspection is an optional add-on for Twin-Path® slings. If crushing or heat damage has occurred to the sling, the fiber optic cable will no longer have the ability to transmit light from one end to the other. This indicates to the inspector that the sling should be removed from service and returned for factory inspection. The fiber optic cable will conduct light using natural, overhead, or flashlight sources.


Sling can fail if damaged, misused or overloaded. Inspect before use. Damaged sling shall not be used. Use only if trained. Do not exceed rated capacity. Protect sling from being cut by load edges, corners, protrusions and abrasive surfaces. Avoid exposure to acid, alkali and temperature over 80°C. DEATH or INJURY can occur from improper use or maintenance.

Rifled Cover® Technology

US Patent #7,926,859

Rifled Cover® Technology is a major patented breakthrough only available on Slingmax® Twin-Path® high-performance fiber roundslings. Rifled Cover® Technology works like the inside of a rifle barrel, where the bullet spins as it leaves the muzzle of the gun. The helical winding of the core fibers significantly improves strength and efficiency.

Twin-Path® high-performance roundslings with patented Rifled Cover® Technology yield three major advantages:

  1. Increased strength-to-weight ratio. 17% increased breaking strength with the same amount of core yarn.
  2. Consistent and predictable breaking strength for every sling.
  3. Repeatability in the manufacturing process.

Covermax® Covers

Twin-Path® roundslings are made with a Covermax® Cover. The Covermax® Cover is made with a heavy-duty, double-layer industrial nylon material. The outside cover is green and the inside cover is red. If damage on the green cover allows red to show through, return the sling for factory inspection and repair. This cover has been tested to provide the best ultraviolet (UV) protection and the best abrasion protection on any commercially-available synthetic lifting sling.