29 C.F.R. § 4.117
(b) Further, contracts principally for remanufacturing of equipment which is so extensive as to be equivalent to manufacturing are subject to the Walsh-Healey Act. Remanufacturing shall be deemed to be manufacturing when the criteria in paragraph (b)(1) or (2) of this section are met.
(1) Major overhaul of an item, piece of equipment, or materiel which is degraded or inoperable, and under which all of the following conditions exist:
(2) Major modification of an item, piece of equipment, or materiel which is wholly or partially obsolete, and under which all of the following conditions exist:
(3) Remanufacturing does not include the repair of damaged or broken equipment which does not require a complete teardown, overhaul, and rebuild as described in paragraphs (b)(1) and (2) of this section, or the periodic and routine maintenance, preservation, care, adjustment, upkeep, or servicing of equipment to keep it in usable, serviceable, working order. Such contracts typically are billed on an hourly rate (labor plus materials and parts) basis. Any contract principally for the work described in this paragraph (b)(3) is subject to the Service Contract Act. Examples of such work include: