This 20mm x 20mm aluminium box section is perfect for building work, shelving, fencing and more. It has excellent corrosion resistance, fair weldability and a mill finish. You can expect industry-leading quality and service from metals4U. We are the UK’s leading online metal supplier for a reason: we are specialists in metals, mild steel and aluminium and offer same-day dispatch so you can get materials on-site quickly. We are trusted by tradespeople, contractors, and hobbyists to deliver quality 20mm x 20mm aluminium box section, so they can get the job done quickly. You can buy 20mm x 20mm aluminium box section up to 6,000mm in length, or use our free custom cutting service to meet more specific requirements.