The base is generally cast iron. Relatively sliding are generally forgings, mainly depends on your specific requirements, parameters. Coastal costs are higher. Chongqing is an old heavy industry city, Chengdu's high precision processing is also good. Chongqing's Geleshan, Dazhulin, Shuangshan, Bishan and many other machine shops. Chengdu's Longquanyi, Xindu, high-tech western district, etc., Sichuan's Mianyang, Yibin, etc. are many.
If your process and so on has not been set down, then it is recommended to find some old state-run factories or universities to set the first process. For example, Chongqing Institute of Science and Technology, Qingping plant Changan Group and so on. Sichuan's 420 (Chengfa),167 (Lingchuan), 132 (Chengfei) and so on.