This solicitation is a total small business set-aside for the manufacture of a Seat Retainer for a 4-inch Hull and Backup Valve, designated as Special Emphasis Level I material for a crucial shipboard system. The item must be produced to strict specifications, including QQ-N-281 Class A material, quantitative chemical and mechanical analysis, thread inspection per FED-STD-H28, and welding per applicable Navy specifications. The contractor must maintain an ISO-9001 quality system with specific calibration requirements, provide material traceability and certification data, and comply with extensive quality assurance and Government source inspection provisions. The award will be a DO-rated order for national defense and will be issued bilaterally, requiring written acceptance. Past performance will be considered in the evaluation.