New Stedman VSI Anvil Ring Design Externally Adjustable and Visually Indicated – Anvil Ring for Stedman Vertical Shaft Impactors The new, patent-pending VSI Anvil Ring is easily adjustable by an external threaded jack bolt. Anvil ring position is verified externally by an integral position indicator. Internal access to the crusher is not required for anvil ring adjustment, increasing safety and lessening downtime. Adjusting the anvil ring position up and down, allows for even wear across the entire wear surface, nearly doubling the life of the anvil ring in many cases. The anvil ring can be re-positioned with common hand tools in half the time previously required.