40x40mm Square Ribbed Tube Insert, 2.6-4mm

These 40x40mm square ribbed tube inserts are designed to provide a clean, secure finish for square tube and box section. Thanks to the flexible lateral ribs running around the shank of the insert, they should be suitable for tube wall thickness of between 2.6 to 4mm metric (6-12 gauge imperial), unless otherwise stated. 

Manufactured from durable LDPE plastic, they are commonly used as protective end caps, tube feet, and finishing plugs across furniture, fabrication, and light industrial applications. They're designed to retain themselves inside tube, with the head sitting over the outer ends of the tube or box section, sitting flush with the outside edges of the tube, providing a neat finished appearance.

Key Features:

• Fits hollow tube or box section with a 40x40mm external dimension
• Manufactured from resilient LDPE
• Ribbed design for secure fitting
• Helps protect floors from exposed tube ends, reducing noise and marking
• Available in multiple colours
• Designed primarily for indoor use but can be used outside but not UV stabilised as standard

Technical Information:

• Tube or box section profile: Square
• External tube size: 40x40mm
• Tube wall thickness: 2.6-4mm
• Suggested internal fit: 32x32mm to 35x35mm approx. (different factors affect this, including coatings, weld lines and tolerance)
• Material: Low-Density Polyethylene (LDPE)
• Fitting type: Push-fit ribbed insert

Suitable for:

• End Stops for Office and Workshop furniture
• Foot Bungs for Chairs and Tables
• Plastic Stoppers for square hollow tubes and box section
• Feet for Display Systems
• Post Caps for Gates and Railings
• Tube End Caps for Light Fabrication projects
• Protective Tube Ends for Finishing
• Ribbed Knock In Inserts for POS and Shopfitting

Tube inserts are always listed the same way that tube is listed because the head of the insert needs to marry up with the outside edges of the tube.  They often come in a variety of wall thicknesses and gauge sizes but if you're unsure on fit, you can click the 'Request Sample' button, or for help measuring your tube, try out this useful sizing pdf.

If this isn't quite right for your application, if for instance you want inserts or feet for an angled chair leg or just simply prefer something with a more enhanced cosmetic head than a bog standard flat insert, then take a look at our range of domed, angled or pyramid head inserts.  We've also got All-Metal Inserts and Square Threaded Inserts for Feet & Castors but if you're not finding what you're needing then just give us a call, drop us an email or use the livechat facility.

   Why not submit your own review?

Submitted by Tony Clarke (8/05/2026)
Arrived promptly well packaged already in use

Quality
Accurate Description
Performance/Suitability
Value for money
Overall Score	5.0 / 5

Frequently asked questions about this item are shown below. Do you have a question? Submit FAQ

Q: please could i have a material data sheet for the part. MT

A: Hello. We requested a material data sheet from our partner factory who have now provided us with a technical drawing (which can already be found on the product page) and advised that the part is made from Polyethylene (PE). I hope this assists but if there is any further information you need then please do not hesitate to get in touch. Kind regards, BPF

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