1. Short title This Act may be cited as the Made in America Shipbuilding Act of 2018 . 2. Domestic shipbuilding requirement (a) In general The head of an executive agency may not enter into a contract related to the acquisition, construction, or conversion of a vessel unless the vessel is to be constructed or converted in the United States. (b) Executive agency defined In this section, the term executive agency has the meaning given the term in section 133 of title 41, United States Code. 3. Domestic sourcing requirement for shipboard components (a) In general Chapter 47 of title 41, United States Code, is amended by adding at the end the following new section: 4713. Domestic sourcing requirement for shipboard components (a) Requirement for United States manufacture (1) Limitation on procurements The head of an executive agency may procure any of the following components for vessels only if the items are manufactured in the United States: (A) In general The following components for vessels: (i) Air circuit breakers. (ii) Welded shipboard anchor and mooring chain with a diameter of four inches or less. (iii) Auxiliary equipment, including pumps, for all shipboard services. (iv) Propulsion system components (engines, reduction gears, and propellers). (v) Shipboard cranes. (vi) Spreaders for shipboard cranes. (vii) Capstans. (viii) Winches. (ix) Hoists. (x) Outboard motors. (xi) Windlasses. (B) Other components The following components of vessels, to the extent they are unique to marine applications: gyrocompasses, electronic navigation chart systems, steering controls, pumps, propulsion and machinery control systems, and totally enclosed lifeboats. (C) Valves and machine tools Items in the following categories: (i) Powered and non-powered valves in Federal Supply Classes 4810 and 4820 used in piping for naval surface ships and submarines. (ii) Machine tools in the Federal Supply Classes for metal-working machinery numbered 3405, 3408, 3410 through 3419, 3426, 3433, 3438, 3441 through 3443, 3445, 3446, 3448, 3449,