A palisade fence runs vertical spear shafts, typically 25x25x1.2 SHS, welded between a top and bottom horizontal rail. The shafts pass through or sit flush with the top rail and finish in a tip: a crimped pyramid (formed by pressing the tube end flat) or a cast arrowhead bolted or welded to the shaft. The combination is hard to climb (the tip refuses a grip) and hard to cut (the shafts are sized for security, not just looks).
Standard residential and commercial palisade runs at 1800 to 2400 mm overall height, with shaft spacing between 100 and 150 mm face-to-face. Heritage variants run taller (up to 3000 mm) with cast arrowheads and decorative collars. Commercial security palisade is hot-dip galvanised then powder-coated black or dark green; heritage palisade is often left in raw HDG with a wax topcoat.
Australia's palisade market splits between the security category (BlueScope and OneSteel posts, generic spear shafts, contractor install) and the heritage category (architectural specifiers, cast iron-look tips, residential street frontages). CAD60's spear-top models cover both ends of that spectrum: square SHS shafts with crimped tips for the security build, round bar with cast arrowheads for the heritage build, all from the same parametric configurator.