GST classification of harvesting and threshing machinery confirmed; amendments and a no-refund retrospective tax rule apply. GST classification places harvesting or threshing machinery, including straw or fodder balers, grass or hay mowers, and parts thereof under heading 8433 in Schedule 2 as taxable goods; amendments have modified the tariff scope and Section 132 of the Finance Act, 2020 applies a retrospective central tax treatment to items used as parts of agricultural machinery (headings 8432, 8433, 8436) for a prior period with no refund allowed.