Used on 79a truck, 5-ton m939 series.. 2a 1st end thread class 12 1st end thread quantity per inch zinc or cadmium surface treated un 1st end thread series
3a 1st end thread class 16 1st end thread quantity per inch flange shape heptagon with 7 bolt holes 0.257 in. dia anodize surface treated un 1st end thread series