A heat-treated aluminium alloy that balances strength, corrosion resistance, light weight and formability. It is the standard alloy for automotive and industrial pipework - it will not rust, needs no coating, sheds heat well, and handles engine bay vibration and heat cycling without work-hardening or cracking.

1 metre straight tube, beaded and unbeaded straight hose joiners, T-piece three-way joiners, 45, 90, 135 and 180 degree elbows, an alloy water sensor adaptor, aluminium heat shields, and an off-cut mixed box of assorted tube sections. Sizes run from 8mm to 102mm outside diameter.

-40C to +220C with a 1.6mm wall on our parts. In most installations the limiting component is the hose rather than the metal - our standard silicone runs to +250C, so the aluminium is comfortably within its capability. It is well beyond anything a coolant or charge air system will ask of it.

Weight, cost and heat rejection. Aluminium is a fraction of the weight of steel, cheaper than stainless, and sheds heat faster - which matters in charge air pipework where the whole point is keeping intake temperatures down. It also will not rust, unlike mild steel, so it needs no protective coating.

All three. Cut with a pipe cutter or fine-tooth blade and deburr inside and out so the edge cannot score a hose bore. T6063 TIG welds well, though the heat-affected zone softens slightly. It polishes up nicely and can be anodised or powder-coated - just mask where the hose clamps on, or a thick coating can creep.

Aluminium forms its own protective oxide layer and copes well in a properly maintained system. Trouble comes from old, exhausted coolant with depleted corrosion inhibitors, or running plain water with dissimilar metals in the circuit. Keep coolant to its service interval and the parts will outlast the hoses.