5 Spline Socket Key - Rust-Resistant Alloy Steel - Not for Lug Nuts - 1 Piece About this item 5 SPLINE SOCKET KEY - This 5 spline lug key is a staple addition to your spline socket set. It?s the perfect replacement for a lost or worn-out spline lug bolt socket key. Use or keep a spare so you can readily remove your vehicle?s security lug bolts. ONLY FOR LUG BOLTS - This 5 spline tuner socket only replaces 5-spline, 12x1.5 thread lug bolts. The spline key adapter only fits lug bolts with head diameters measuring 18.5mm (center groove to opposite wall) and 10.8mm (between adjacent center grooves). Refer to pictures for assistance. DURABLE AND RELIABLE - This 5 spline wheel lock key is hard-wearing and designed for repeated use. It is made out of alloy steel with a heat-treated, rust-resistant coating. Easily removes, replaces, and secures compatible 5 spline lug bolts. SOCKET KEY SIZING AND FIT - This spline drive wheel lock key is not compatible with lug nuts of any kind. The head diameter of the 5-spline lug bolt must be exactly 18mm to ensure a secure fit. Hex size of socket key: 19mm (3/4"). ABOUT STANCEMAGIC - We have in-depth knowledge of all of the products that we manufacture and carry. Over the years, we have developed a diverse line of products. We manufacture and sell a wide range of wheel spacers adapters, as well as suspension components.