3a thread class right-hand 0.502" thread length double hexagon extended washer head style 0.117" grip length 28 thread quantity per inch unjf thread series
3a thread class right-hand 0.495" thread length double hexagon head style 1.360" grip length 20 thread quantity per inch bolt-shear temp range is -65 to 900 degrees f. lubrication is cetyl alcohol. chromate surface treated unf thread series