19 C.F.R. § 54.6
Articles predominating by weight of metal, described in § 54.5(a) shall be admitted free of duty upon compliance with the following conditions:
(c) Within 3 years from the date of entry, or withdrawal from warehouse for consumption, the importer shall submit to CBP, either at the port of entry or electronically, a statement from the superintendent or manager of the plant at which the articles were used in remanufacture by melting, or were processed by shredding, shearing, compacting, or similar processing which rendered them fit only for the recovery of the metal content, showing:
(d) If satisfactory proof of use of the articles in remanufacture by melting, or in processing by shredding, shearing, compacting, or similar processing which rendered them fit only for the recovery of the metal content, is furnished within the prescribed time, the entry shall be liquidated without the assessment of duty on the covered articles. If proof is not filed within 3 years from the date of entry, or withdrawal from warehouse for consumption, or the use does not warrant the classification claimed, the entry shall be liquidated without any exemption from duty under subheading 9817.00.80 or 9817.00.90, HTSUS.
As used in this section, the phrase “in connection with the entry” means any time before liquidation of the entry or within the period during which a reliquidation may be completed (§ 113.43(c)). Therefore, a claim for free entry under subheading 9817.00.80 or 9817.00.90, HTSUS, supported by a statement of intent may be filed at any time before liquidation of the entry or within the period during which a valid reliquidation may be completed.
(R.S. 251, as amended, secs. 623, as amended, 624, 46 Stat. 759, as amended (19 U.S.C. 66, 1623, 1624))
[T.D. 80-151, 45 FR 38041, June 6, 1980, as amended by T.D. 84-213, 49 FR 41170, Oct. 19, 1984; T.D. 87-75, 52 FR 20067, May 29, 1987; T.D. 89-1, 53 FR 51255, Dec. 21, 1988; T.D. 95-81, 60 FR 52295, Oct. 6, 1995; CBP Dec. 15-14, 80 FR 61286, Oct. 13, 2015; CBP Dec. 16-26, 81 FR 93016, Dec. 20, 2016]