Check out certifications: Hunt for machining suppliers with field certifications like ISO 9001
http://paulikipedia.ru/index.php/The_Versatility_of_CNC_Machined_Pieces:_Discovering_Typical_Purposes_in_Various_Industries_86382
Verify certifications: Seek out machining suppliers with marketplace certifications like ISO 9001, which makes certain quality management units are set up