Historically, grey cast iron has been a great servant to the mining industry. Many tunnels and shafts still in use today have depended on its strength and longevity.
But – it is brittle. And that brittleness has always called for thick segments, driving up weight, accessibility…and price.
The standard today, is ductile cast iron, or SGI (spherical graphite iron).
Graphite flakes, as used in the past, are responsible for weak areas in the cast – so we use spherical graphite within the molten stage, which distributes pressure more evenly in the final casting. It gives enormous strength and flexibility to our product.
As a result, SGI offers huge advantages over traditional cast iron.
Its flexibility means it has vastly increased resistance to both impact and shock. Vibrations – whether from construction or environment can cause all manner of problems for traditional cast iron tubbing. With the benefit of flexibility, which to a certain degree allow the sections to bend without cracking, Woosung’s SGI tubbing is stronger, thinner, and crucially just as effective at holding back the surrounding earth.
With our outstanding quality control and certification, we are confident we can supply superior tubbing to all projects at highly competitive prices