20pc Black Open End Lug Nuts - 7/16"-20 Thread Size - 0.85" Length - Cone Conical Taper Acorn Seat - Installs with 19mm or 3/4" Hex Socket [APPLICATIONS] Older (prior to 1985) Buick, Chevy, Chevrolet, Oldsmobile, & Pontiac vehicles with 7/16"x20 threaded studs. [SPECIFICATIONS] Pack of 20 | Total Length: 0.81 inches | Seat Type: Cone Seat | Thread Size & Pitch: 7/16"x20 | Color: Black | See Diagram Image for Details. [MANUFACTURING] Manufactured with cold forged steel. Additional Heat Treating ensures dependable strength & durability. Precisely machined threads ensure a perfect fit on your vehicle's wheel studs. Special coating provides exceptional corrosion resistance and appearance. [NUT SIZE] Verify the thread size of the nuts on your vehicle. Various years/models come with different thickness nuts and thread pitches. [SEAT TYPE] There are a variety of "Lug Seats", please make sure your wheels take Cone Seat shaped nuts. (See Diagram Image for details)