PRODUCT SPECIFICATIONSPart #: 0000-128039Fastener Type: Square Head Machine BoltSize Description: 3/4"-10 x 3 1/2" (PT)Diameter/Nominal Size: 3/4"Length: 3 1/2"Wrench Size/Across Flats: 1.088-1.125"Width Across Corners: 1.494-1.591"Head Height: 0.476-0.524"Thread Pitch: 10Thread Pitch Type: CoarseThread Direction: RightThread Coverage: PartialSystem of Measurement: InchGrade: A (2)Material: Low Carbon SteelFinish: Plain Finish (No Plating)Head Type: SquareDrive Type: External SquareStandards Met: A307Average Piece Weight: 0.5370000 lbs.Square head bolts, or square head machine bolts offer a large bearing area for positive gripping; primarily used nowadays for aesthetic projects that create a rustic look or to match existing fasteners; comes in both fully threaded and partially threaded pitches. Square head bolts are sometimes selected over hex heads because the head will fit neatly in a channel.