12.9 grade of track bolt and nut,HRC38-42 8H7504---6S3419,4K7038---7K2017,7H3597--- ... .S.I. There are 10.9,12.9 class of track bolt and nut,plow bolt and nut,segment bolt with ... .productShow(); oProductShow.init( { 'aImgSrc': aBigImageSrc } ); } )(); Komatsu 12.9 Grade of Track bolt with nut