... tapping screw,nylock patch screw,waterproof sealing screws,color head screw and precision shaft and pins.all kinds of ... . 15 years export experience5. Best services6. Excellent technology self taping screw7. Short lead time8. Be used in high end industries ... forming, rolling, heat treatment, surface treatment, thread rod and head painting, checking and selecting, EDI ultra-pure water treatment, vacuum ...