Schedule of Segment Reporting Information, by Segment (Details) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 30, 2016		Jun. 30, 2015	Jun. 30, 2016		Jun. 30, 2015	Dec. 31, 2015
Net sales	$ 9,820,730		$ 9,206,174	$ 19,417,125		$ 18,489,965
Depreciation	308,122		314,830	607,477		627,475
Segment operating profit	1,832,645		1,422,355	3,492,205		2,684,991
Selling and administrative expenses	(667,149)		(579,611)	(1,352,411)		(1,170,607)
Interest income	9,563		6,217	18,322		13,050
Capital expenditures	339,315		473,171	886,855		886,855
Accounts receivable, net	6,278,622	[1]	5,906,646	6,278,622	[1]	5,906,646	$ 5,438,332	[1]
Inventories, net	4,991,208		5,010,529	4,991,208		5,010,529	4,538,212
Property, plant and equipment, net	12,028,322		11,133,656	12,028,322		11,133,656	$ 11,698,443
Other assets	7,791,988		7,829,216	7,791,988		7,829,216
Fastener
Net sales	8,858,036		8,276,263	17,305,365		16,676,760
Depreciation	268,450		275,612	529,273		549,364
Segment operating profit	1,487,070		1,129,353	2,713,431		2,147,400
Selling and administrative expenses	0		0	0		0
Interest income	0		0	0		0
Capital expenditures	298,237		108,726	459,543		459,543
Accounts receivable, net	5,979,118		5,546,859	5,979,118		5,546,859
Inventories, net	3,976,986		4,148,131	3,976,986		4,148,131
Property, plant and equipment, net	9,887,971		9,175,077	9,887,971		9,175,077
Other assets	0		0	0		0
Assembly Equipment
Net sales	962,694		929,911	2,111,760		1,813,205
Depreciation	22,032		20,097	43,614		40,194
Segment operating profit	345,575		293,002	778,774		537,591
Selling and administrative expenses	0		0	0		0
Interest income	0		0	0		0
Capital expenditures	7,180		344,367	399,142		399,142
Accounts receivable, net	299,504		359,787	299,504		359,787
Inventories, net	1,014,322		862,398	1,014,322		862,398
Property, plant and equipment, net	1,613,944		1,471,665	1,613,944		1,471,665
Other assets	0		0	0		0
Unallocated Corporate
Net sales	0		0	0		0
Depreciation	17,640		19,121	34,590		37,917
Segment operating profit	0		0	0		0
Selling and administrative expenses	(667,149)		(579,611)	(1,352,411)		(1,170,607)
Interest income	9,563		6,217	18,322		13,050
Capital expenditures	33,898		20,078	28,170		28,170
Accounts receivable, net	0		0	0		0
Inventories, net	0		0	0		0
Property, plant and equipment, net	526,407		486,914	526,407		486,914
Other assets	$ 7,791,988		$ 7,829,216	$ 7,791,988		$ 7,829,216

[1] Net of allowance of $150,000.