Vintage-style Hardware Traditional-style 20 TPI thread Made of solid steel  3/8" size from point to point on rod 5/16" thick square shaft Swivel-style spindle Product Description Specs An old-style threaded swivel spindle rod for doorknobs that use a privacy (locking) mechanism. Made of solid steel, this spindle is sturdy & durable. This particular spindle has a size of 3/8" - 20 threads per inch (TPI), but has a little extra thicker square size (5/16"). Excellent for your reproduction doorknobs, or just a replacement for your old chewed-up spindles.     Hardwick & Sons is pleased to offer vintage-style hardware for the many people who desire to fashion their homes with charm, quality, & style. The traditional-style hardware that we showcase are true & faithful reproductions of classic hardware pieces found in the many homes from across America throughout the past century. Product Thickness Thread Size Overall Size Size of Spindle Square (measured on the flats) Model # Door Spindle 3/8" 20 TPI 3-1/2" Long 5/16" (8 mm) BMH8843-20X Door Spindle 3/8" 20 TPI 4" Long 5/16" (8 mm) BMH8778-20X   For California Residents: WARNING: Cancer & Reproductive Harm - www.P65Warnings.ca.gov WARNING: Drilling, sawing, sanding or machining wood products can expose you to wood dust, a substance known to the State of California to cause cancer. Avoid inhaling wood dust or use a dust mask or other safeguards for personal protection. For more information go to www.P65Warnings.ca.gov/wood