Item NameDin 931 Hexagon Head BoltClassScrew,nut,bolt,washer,thread rod,etc.GradeGR1、GR2、GR3、GR4、GR5、GR7、GR11、GR12、GR23;StandardDIN931SizeM8SurfacePolishing, Anodizing, Black oxide Test Ultrasonic test (UT)PackingWooden CaseApplicationChemical, Industry, Petroleum, Aircraft