Schedule of Segment Reporting Information, by Segment (Details) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2015		Sep. 30, 2014	Sep. 30, 2015		Sep. 30, 2014	Dec. 31, 2014
Net sales	$ 9,018,272		$ 8,995,825	$ 27,508,237		$ 28,446,927
Depreciation	316,120		313,764	943,595		932,500
Segment operating profit	1,131,711		1,267,231	3,816,702		4,065,780
Selling and administrative expenses	(509,169)		(504,849)	(1,679,776)		(1,586,833)
Interest income	5,929		6,375	18,979		19,237
Capital expenditures	455,262		549,049	1,342,117		1,349,136
Accounts receivable, net	5,902,138	[1]	5,961,305	5,902,138	[1]	5,961,305	$ 5,669,654	[2]
Inventories, net	4,864,052		5,282,751	4,864,052		5,282,751	5,162,474
Property, plant and equipment, net	11,254,163		10,824,669	11,254,163		10,824,669	$ 10,877,995
Other assets	8,351,574		7,543,989	8,351,574		7,543,989
Fastener
Net sales	8,153,422		8,295,936	24,830,182		26,148,265
Depreciation	276,252		279,258	825,616		829,612
Segment operating profit	893,862		1,110,078	3,041,262		3,507,230
Selling and administrative expenses	0		0	0		0
Interest income	0		0	0		0
Capital expenditures	360,898		532,879	820,441		1,302,214
Accounts receivable, net	5,536,738		5,615,498	5,536,738		5,615,498
Inventories, net	3,959,195		4,479,552	3,959,195		4,479,552
Property, plant and equipment, net	9,259,723		9,199,056	9,259,723		9,199,056
Other assets	0		0	0		0
Assembly Equipment
Net sales	864,850		699,889	2,678,055		2,298,662
Depreciation	20,097		16,066	60,291		48,198
Segment operating profit	237,849		157,153	775,440		558,550
Selling and administrative expenses	0		0	0		0
Interest income	0		0	0		0
Capital expenditures	49,119		0	448,261		21,540
Accounts receivable, net	365,400		345,807	365,400		345,807
Inventories, net	904,857		803,199	904,857		803,199
Property, plant and equipment, net	1,482,052		1,110,475	1,482,052		1,110,475
Other assets	0		0	0		0
Unallocated Corporate
Net sales	0		0	0		0
Depreciation	19,771		18,440	57,688		54,690
Segment operating profit	0		0	0		0
Selling and administrative expenses	(509,169)		(504,849)	(1,679,776)		(1,586,833)
Interest income	5,929		6,375	18,979		19,237
Capital expenditures	45,245		16,170	73,415		25,382
Accounts receivable, net	0		0	0		0
Inventories, net	0		0	0		0
Property, plant and equipment, net	512,388		515,138	512,388		515,138
Other assets	$ 8,351,574		$ 7,543,989	$ 8,351,574		$ 7,543,989

[1] Net of allowance of $146,000.

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