CARRIAGE BOLT MUSHROOM HEAD SQUARE NECK BOLTS (CARRIAGE BOLT ) CARRIAGE BOLTS 1),STANDARD:ISO ,AISI.2),SIZE:3/16 TO 3/4 INCH3),MATERIAL: CARBON STEEL4),GRADE: (GR2-GR5)CARRIAGE BOLT1).FINISHED :PLAIN ,ZINC PLATED ,BLACK ,HDG2)THREAD :UNC ,AND BSW3) GRADE :GR2 GR54) DIAMETER : 3/16 TO 3/4 INCH5) LENGTH : 1/2 TO 20 INCH CARRIAGE BOLTS