... 10 years experience of springs production 3.OEM customization springs Heavy duty compression springs with large diameter :1.10 years experience of ... product diameter 0.08mm-8.0mm6.CNC spring machine main equipment: CNC502,CNC620,CNC650,MEC,CNC 8HS,grinding head machine, heat ... ISO9001 and ISO14001 quality and environmental system certification in 2008 Heavy duty compression springs with large diameter