INVENTORIES - Schedule of inventories (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Jun. 30, 2020
Inventory Disclosure [Abstract]
Raw materials and supplies	$ 29,271	$ 26,255
Goods in process and finished parts	16,096	13,694
Finished goods	37,344	37,579
Total, before LIFO Reserve	82,711	77,528
LIFO reserve	(22,139)	(24,541)
Total inventories, gross	$ 60,572	$ 52,987

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Amount before valuation and LIFO reserves of completed merchandise or goods expected to be sold within one year or operating cycle, if longer.

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Gross amount, as of the balance sheet date, of merchandise, goods, commodities, or supplies held for future sale or to be used in manufacturing, servicing or production process.

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Amount by which inventory stated at last-in first-out (LIFO) is less than (in excess of) inventory stated at other inventory cost methods.

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Amount after valuation and LIFO reserves of inventory expected to be sold, or consumed within one year or operating cycle, if longer.

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Gross amount of unprocessed materials to be used in manufacturing or production process and supplies that will be consumed.

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Amount before valuation and LIFO reserves of merchandise or goods in the production process expected to be completed within one year or operating cycle, if longer.

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