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
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.
Frequently Asked Questions
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In most cases we have the facilities to offer you different colours of a product, specific to your requirements. Minimum order quantities may apply depending on the manufacturing technique in question, but please get in touch with any queries you may have.
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If you're new to our website you may want to check out our frequently asked questions section for answers to common customer queries.
While browsing the website you may come across abbreviations used for material names that you are unfamiliar with. You can find an explanation for these in our material abbreviations guide.
