100 x 100mm x 600mm Spike This Fencefix post spike is suitable for timber measuring 100 x 100mm & is suitable for most ground conditions. Like the rest of the Fencefix range this post spike is made with longevity & quality in mind. It is produced with an anti-corrosion coating to protect it from heat & moisture. The Fencefix post spike has 3 fins which can make it easier to insert into the ground as it helps to minimise twisting.