3/8 x 4 Alloy Steel Socket Head Shoulder Screw (Stripper Bolt) with Nylon Insert gives engineers a stripper bolt option for applications where the shoulder geometry is central to movement or location. The important engineering feature is the shoulder, which supports positioning and movement while the threaded end retains the fastener. Typical applications include tool and die work, mold-related fixtures, guide mechanisms, and service parts. For maintenance teams, the nylon insert can help address loosening concerns in equipment subject to vibration or repeated motion. Repair technicians may source this part for replacement applications where motion control and retention both matter. Selection should follow the required shoulder diameter, shoulder length, material, and assembly function shown for the part. Common sourcing contexts include replacement maintenance, fixture construction, and OEM production support. Call Cold Headers at 773-775-7900 or email Sales@coldheaders.com for pricing, availability, or a quote.