Pair of 4" replacement door knob spindles with 16 course threads per inch, for repairing or upgrading door knob sets. Each spindle is a square metal bar threaded along its corners, in a bright silver finish. The precision-cut thread of 16 course threads per inch gives a secure, wobble-free connection for most standard antique and reproduction door knobs. The spindles are high-strength, industrial-grade metal built for years of daily wear, with tensile strength that resists snapping and stripping, and a corrosion-resistant finish keeps door handles turning smoothly and securely. Sold as a pair to serve two door sets, they suit historical restoration, modern interior doors, high-traffic doors and professional hardware upgrades. Catalogue code: GMC-SPINDLX-K