civiss vletric fasteners will generally be identified by markings on the bolt head and nut face The following igure displays the different types of identification that will be found on GM vehicles Most metric asteners will be identified There are however some exceptions MANUFACTURES iuuivieen Repmzsems sou srneivcm IDENTIFACTION F I ism M I L J I D I 9 8 I 9 I L I iviemic sou ioenriricmioixiy NUT STRENGTH 1976 USAGE ONLV IDENTIFICATION I I I O O S I I L J Memic Nur IDENTIFICATION Iommon metric fastener strength property classes are 9 8 and 10 9 with the class identification embossed on the head of each bolt Customary inch strength classes range from grade 2 to 8 with ine identification embossed on each bolt head Markings correspond to two lines less than the actual grade i e grade 7 bolt will exhibit 5 embossed lines on the bolt head Some metric nuts will e marked with single digit strength identification numbers on the nut face The following figure llustrates the different strength markings v v v 1 GRADE 2 GRADE 5 GRADE 7 GRADE 8 GM 200 M IGM 280 M GM 290 M GM 300 M Customary inch bolts Identification marks correspond to bolt strength Increasing numbers represent increasing strength 1 za 1 za za 1 Q Q Q1 Q1 Gr 1 1 1 Metric Bolts Identification class numbers correspond to bolt strength Increasing numbers represent increasing strength WAREl lOUSlNG AND DISTRIBUTION D V SlON OF GENERAL MOTORS CClRFORATlON CHEVROLET lO M 2 REV 5 81