surface treatment:plain,galvanized,black grade:4.8,8.8,10.9 standard:GB,DIN,UNITED STATES STANDARD Specifications:1) ... , black, plain2) Diameter: M6 - M243) Length: 65mm - 200mm4) Grade: 4.8 grade ,8.8 grade,10.9grade5) standard:GB,DIN,UNITED STATES STANDARD5) Thread ... customers' requirementsBelow pic is yellow zinc plated bolt DIN933 DIN931 4.8 8.8 10.9 BOLT(zinc plated,black,plain)