Statements of Comprehensive Income - USD ($)	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Net sales	$ 22,521,012	$ 27,471,365
Cost of sales	17,806,444	20,099,683
Gross profit	4,714,568	7,371,682
Selling, general and administrative expenses	3,188,112	3,028,449
Operating Income	1,526,456	4,343,233
Other income
Interest income	88,836	33,782
Other	36,113	85,492
Total other income	124,949	119,274
Income before provision for income taxes	1,651,405	4,462,507
Provision for income taxes	515,669	1,286,706
Net income	1,135,736	3,175,801
Other comprehensive income, net of tax:
Unrealized (loss) gain on investment securities	(2,191)	2,978
Total comprehensive income	$ 1,133,545	$ 3,178,779
Net income per share:
Basic	$ 0.49	$ 1.39
Diluted	$ 0.49	$ 1.38
Weighted average number of shares outstanding:
Basic	2,312,870	2,285,686
Diluted	2,324,838	2,302,034