Guiyang Special Steel Rock Tools (GSS) was established in 1958,the largest professional manufacture of rock drilling hollow steel and rock tools in the world. GSS Rock Tools have more than 300,000 square meter production scale, service by senior technical engineers; hundreds of artisan, this team has strong capability of research and development, production, sales and after service. Since 2018 GSS start service oversea customers by ourselves, so that give more support and better services,we were warmly welcome to visit our factory and contact us !