PRODUCT SPECIFICATIONSPart #: 0000-113186Fastener Type: Regular Square NutSize Description: 3/8"-16Diameter/Nominal Size: 3/8"Thickness: 21/64" (0.310-0.346")Wrench Size/Across Flats: 5/8" (0.606-0.625")Width Across Corners: 0.802-0.884"Thread Pitch: 16Thread Pitch Type: CoarseThread Direction: RightSystem of Measurement: InchGrade: 2Material: Low Carbon SteelFinish: Zinc PlatedDrive Type: External SquareUsed with: Bolts/Screws up to Grade 5Average Piece Weight: 0.0262800 lbs.Nuts are almost always used in conjunction with a mating bolt to fasten multiple parts together; kept together by a combination of their threads' friction, a slight stretching of the bolt, and compression of the parts to be held together.