Statements of Comprehensive Income (Unaudited) - USD ($)	3 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Net sales	$ 7,265,515	$ 5,923,819
Cost of sales	6,138,141	4,787,471
Gross profit	1,127,374	1,136,348
Selling, general and administrative expenses	914,626	1,084,212
Operating income	212,748	52,136
Other income:
Interest income	15,217	32,161
Other	3,128	15,328
Total other income	18,345	47,489
Income before provision for income taxes	231,093	99,625
Provision for income taxes	41,269	17,849
Net income	189,824	81,776
Other comprehensive (loss) income, net of tax:
Unrealized (loss) gain on investment securities	(1,674)	197
Total comprehensive income	$ 188,150	$ 81,973
Net income per share:
Basic	$ 0.08	$ 0.03
Diluted	$ 0.08	$ 0.03
Weighted average number of shares outstanding:
Basic	2,402,633	2,387,408
Diluted	2,402,633	2,396,256
Dividends per share:	$ 0.25	$ 0.25