What it is
AN525 washer head screw, Washer head, recessed (R), .250-28UNF-3A (1/4-28) (dash 416), length 3/8" (±1/32), grip 1/32" (G)
Equivalents
No equivalent on file: no maker document names one and the government catalog lists none on its stock number.
Install tooling, by who made the part
Not documented for this part number. Ask a tooling specialist →

Reference only: the drawing and its process spec govern. How to read this

Full detail: decode, cited documents, every stock number