Aperture
The size of the hole in a mesh panel, quoted as height x width. Smaller apertures resist climbing and cutting; larger ones are cheaper and more open.
Also called: mesh aperture, mesh size
Aperture is the size of the hole in a mesh panel, quoted as height by width. It is the number that decides how secure a mesh fence actually is, and it matters more than the wire thickness.
What the sizes mean in practice
- 200 x 50mm — twin wire, profile and most commercial mesh. Fingers go through, a toe does not. Deters climbing, looks open.
- 12.7 x 76.2mm — 358 prison mesh. Nothing goes through, and bolt cropper jaws will not fit around a wire.
A wide aperture on thick wire is easier to climb than a tight aperture on thinner wire, which is why 358 mesh on 4mm wire outperforms twin wire on 8mm for anti-climb purposes. Read the aperture first.