PennEngineering® Large Knob, Spring-loaded - Types PF11MF and PF12MF - Unified PF11MF-440-0

The PF11MF-440-0 is a spring-loaded, flare-mounted captive panel screw with a knurled metal cap, designed for installation into thin panels where flush mounting and easy service access are required. It features a shoulder on the retainer to provide a positive stop during installation and includes an anti-cross-threading design. The screw has a #4-40 thread size, hardened carbon steel body, aluminum retainer and knob, and a 300 series stainless steel spring. The component installs flush on the back side of the panel and accommodates a minimum clearance hole diameter of 0.170 inches. A DuraBlack finish is available as an option. Installation requires a countersunk hole and specific tooling, with a minimum flare dimension of 0.015 inches at a 90-degree angle.