Statements of Comprehensive Income - USD ($)	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Net sales	$ 36,477,851	$ 32,517,883
Cost of sales	29,414,678	24,855,631
Gross profit	7,063,173	7,662,252
Selling, general and administrative expenses	4,410,234	3,808,395
Operating Income	2,652,939	3,853,857
Other income
Interest income	167,682	160,650
Other	61,012	54,569
Total other income	228,694	215,219
Income before provision for income taxes	2,881,633	4,069,076
Provision for income taxes	538,939	993,279
Net income	2,342,694	3,075,797
Other comprehensive income, net of tax:
Unrealized gain (loss) on investment securities	5,050	(2,750)
Total comprehensive income	$ 2,347,744	$ 3,073,047
Net income per share:
Basic	$ 0.99	$ 1.32
Diluted	$ 0.98	$ 1.31
Weighted average number of shares outstanding:
Basic	2,372,945	2,333,885
Diluted	2,389,228	2,348,307