Jam thickness locknuts are about half the height of standard nylon-insert locknuts. Use in light duty low-clearance applications. The nylon insert grips the bolt to resist loosening without damaging threads. They're reusable, but their holding power lessens with each use. Max Operating Temperature of 250° F. 18-8 (300 Series) Stainless Steel offer resistance to general atmospheric corrosion in damp environments and exterior applications.