Key clamp fittings are made to fit two standard tube outside diameters: 42.4 mm (Size C) and 48.3 mm (Size D). Size D suits 48.3 mm tube commonly used for handrails and guardrails, while Size C fits the slimmer 42.4 mm tube. Always match the fitting size to the tube's outside diameter, not its internal bore.

No, key clamp fittings require no welding — they fix onto steel tube with an integral grub screw tightened by a hex/Allen key. This allows structures to be assembled, adjusted and dismantled on site with only basic hand tools. It also avoids hot works, so no specialist fabrication is needed.

A typical straight handrail run needs one fitting at each end plus one at every upright, so a run with two end posts and one intermediate post uses around five to seven fittings. Count each junction — corners, tees and wall flanges each take one fitting. GeZu Impex supplies elbows, tees, flanges and base plates so you can build any layout.

Key clamp fittings are made from hot-dip galvanised malleable (cast) iron, giving strong impact resistance and long-term corrosion protection. The galvanised coating suits outdoor and permanent installations such as external handrails, balustrades and barriers. Malleable iron withstands repeated tightening of the grub screw without cracking.