Product Name :High quality galvanized black phosphate gypsum drywall screws for metal and wood Material :Stainless/Carbon steel Finish:Black, Polish Measurement system:Metric Head Style:Pan Standard: DIN Grade :4.8/8.8/10.9/12.9 Certifications Main Products Testing Laboratory We have Magnetic Powder Detector, Material Testing Machine, Metallographic Microscope, such testing instruments, guarantee product high quality and beautiful appearance.The quality control is strictly performed from buying raw materials in warehouse to different machining procession and to final packing. Production Process First, we have our own High-precision Digital Machining center for mould making in special Mould Workshop, excellent mould make product beautiful appearance…