Inventory (Details) - USD ($)	Aug. 31, 2020	May 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Raw materials	$ 637,444	$ 658,024
Work-in-process	8,472,445	8,586,404
Finished goods	540,503	963,009
Gross inventory	9,650,392	10,207,437
Less allowance for obsolescence	100,000	100,000
Net inventory	$ 9,550,392	$ 10,107,437

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

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