Flex Protect Strain Relief Bushings

Our Flex Protect Strain Relief Bushings, sometimes referred to as cable bend protectors or spring cable bushings, are precision-engineered components designed to protect cable integrity at panel exits. Also known as flex protect strain relief bushings, nylon strain relief bushings or UL94V-2 bushings, these fittings are essential for guarding flat and round cables in industrial control systems, electrical cabinets, consumer appliances and telecom enclosures across the UK. Featuring a patented spring-arm design and UL 94V-2 Nylon 6/6 construction, they prevent kinks, pulls and twists—extending service life while maintaining compliance with flame-retardant standards.

Available materials & style options

• UL 94V-2 Nylon 6/6 (black)
• Round or flat cable versions (suffix ‘R' or ‘F')
• Panel hole diameters: 12.7–13.1 mm, 15.9 mm, 19.0 mm (and more)
• Cable dim range: 6.4 mm to 10.9 mm depending on variant
• Loop lengths: approx. 50.4 mm, 53.6 mm, 66 mm

Key features & benefits

• Spring-arm design: Absorbs lateral stress and ensures smooth bending radius without sharp cable kinks
• Flame-retardant Nylon: UL 94V-2 rated, offering both insulation and fire safety
• Push-fit installation: Tool-free mounting into pre-drilled panels, with optional installation pliers available
• Strain relief protection: Guards against cable pull-out and absorbs mechanical force, proven to pass CSA's 50,000-cycle vacuum cleaner bend test
• Wide temperature range: Reliable between −18 °C and +105 °C
• Compliance certified: UL File E15331, CSA File 8919, and UL859 for cord flexion
• Cost-effective: Competitively priced alternative to Heyco Lockit snap-in bushings

Technical specifications (example for STRB272R)

• Panel hole diameter: 12.7–13.1 mm
• Panel thickness compatibility: ~1.6 mm
• Cable diameter range: 6.4–7.4 mm (round)
• Total length: ~50.4 mm

Common UK use cases

• Strain relief for appliance power leads such as vacuum cleaners and kitchen equipment
• Cable protection in industrial control panels and distribution boards
• Strain control in telecom and data cabinets
• Routing cables through machinery and vending equipment without wear
• Bulk installations in OEM manufacturing and wiring harness assemblies

Related Vital Parts products

• RDD Flex Protect Strain Relief Bushings – for double-D shaped panel entries
• Right angle strain relief bushings – for achieving an angled exit from your panel hole

Call Vital Parts

For quick quotes, same-day dispatch, custom sizes, or bulk discounts, call our sales line on 01233 713 581. Businesses can register for a Vital Parts Business Account to benefit from priority shipping, trade pricing, free product samples, credit accounts, and a dedicated account manager.

Further Reading

Visit our Strain Relief Guide to learn why strain relief bushings are important and the difference between standard, liquid tight and lockit versions.