Lug Nuts and Bolts

Lug nuts hold your wheel to the vehicle by clamping force, and getting three specifications right is what generates that clamping force correctly: seat type, thread pitch and length.Seat type is the shape where the nut meets the wheel. Conical or acorn seat is a 60 degree taper and is by far the most common on aftermarket wheels. Ball or radius seat is a rounded seat used by many European manufacturers including VW, Audi and some BMW. Mag or shank seat uses a flat washer face with a long straight shank and is used on many Honda and Toyota factory wheels. Mixing these up is the most common cause of wheels coming loose.Thread pitch has to match your studs exactly. Common pitches are 12x1.5 on Toyota, Honda and most GM, 12x1.25 on Nissan and Subaru, 14x1.5 on modern Ford, GM trucks and Dodge, and 14x2.0 on older Ford. Length matters because you need enough thread engagement, and the rule of thumb is that the stud should engage at least as many threads as the diameter of the stud.Torque to the manufacturer specification with a torque wrench, in a star pattern, and re-torque after 50 to 100 miles. Impact guns overtighten and stretch studs.