Hex Lock Nuts With Nylon Ring-Class 8- Thread Size: M16-2.0, Height 16mm. Dorman Nut. NOT ACQ Rated; NOT FQA Compliant. Callout Size: M16-2.0; Size: M16. Dorman offers a comprehensive variety of nuts for almost any automotive fastening job. All our nuts are constructed of high-quality materials for long-lasting durability.