Available in 1 to 17 treads up to a metre wide. Manufactured in Pre-galvanised tube suitable for most installations or fully hot dipped galvanised for heavy duty or seaside applications.Stair stringers are generally manufactured in pairs and are available in 3 configurations; landing to ground (bolt down base ), landing to ground (inground base), or landing to landing. Standard rising is 175mm and standard going is 250mm. Configuration 1 – Landing to Ground (bolt down footing) Configuration 2 – Landing to Ground (inground footing) Configuration 3 – Landing to Landing Pre-galvanised stringers are made from Duragal or equivalent pre-galvanised RHS and galvanised stair tread brackets. Hot dipped galvanised stringers are first manufactured and then sent to the galvanisers who will immerse the completed fabricated product into molten zinc. This process provides are thicker coating than the pre-galvanised product.The following table shows the number of treads required for various vertical heights and horizontal lengths based on a standard rising is 175mm and a standard going is 250mm.