PennEngineering® Large Knob, Spring-loaded - Types PF11MF and PF12MF - Metric PF11MF-M4-0

The PF11MF series comprises spring-loaded, flare-mounted captive panel screws with a large knob, designed for flush installation on the back side of thin panels, including painted surfaces, and suitable for close centerline-to-edge applications. The screw is made of hardened carbon steel with a zinc-plated finish per ASTM B633, the retainer and knob are aluminum, and the spring is 300 series stainless steel. It features an anti-cross-threading design and a shoulder providing a positive installation stop. For M4 thread size, the minimum sheet thickness is 1.83 mm, the countersunk hole diameter is 6.76 mm, and the installed height above the sheet is 13.06 mm. The retainer pullout force is 800 N in cold-rolled steel. The part is installed using a countersunk hole with a 90° chamfer and specific tooling for flare-mounting.