Reportable Segments (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 29, 2012	Sep. 29, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Oct. 01, 2011	Jul. 02, 2011	Apr. 02, 2011	Dec. 29, 2012	Dec. 31, 2011	Jan. 01, 2011
Segment Reporting Information [Line Items]
Sales to unaffiliated customers	$ 35,809,652	$ 39,644,050	$ 41,559,589	$ 40,495,894	$ 38,057,309	$ 36,089,946	$ 35,520,182	$ 33,188,612	$ 157,509,185	$ 142,856,049	$ 130,130,360
Inter-segment revenue									3,185,578	3,208,348	3,520,945
Operating profit									13,551,423	8,712,180	8,511,719
Interest expense									(369,357)	(231,481)	(266,297)
Other income									42,452	26,230	2,996
Income before income taxes									13,224,518	8,506,929	8,248,418
Assets	115,854,150				106,699,974				115,854,150	106,699,974	102,353,480
Depreciation and amortization									3,439,800	3,707,216	3,942,639
Capital expenditures									4,149,943	3,377,620	4,626,150
Currency translation adjustment	(2,730)				7,132				(2,730)	7,132	(20,536)
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	35,809,652	39,644,050	41,559,589	40,495,894	38,057,309	36,089,946	35,520,182	33,188,612	157,509,185	142,856,049	130,130,360
Assets	115,854,150				106,699,974				115,854,150	106,699,974	102,353,480
United States [Member]
Segment Reporting Information [Line Items]
Sales to unaffiliated customers									120,604,363	107,472,590	106,141,008
Assets	95,441,029				86,844,921				95,441,029	86,844,921	84,804,542
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									120,604,363	107,472,590	106,141,008
Assets	95,441,029				86,844,921				95,441,029	86,844,921	84,804,542
Foreign [Member]
Segment Reporting Information [Line Items]
Sales to unaffiliated customers									36,904,822	35,383,459	23,989,352
Assets	20,413,121				19,855,053				20,413,121	19,855,053	17,548,938
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									36,904,822	35,383,459	23,989,352
Assets	20,413,121				19,855,053				20,413,121	19,855,053	17,548,938
Industrial Hardware [Member]
Segment Reporting Information [Line Items]
Sales to unaffiliated customers									72,268,559	66,119,119	57,527,864
Inter-segment revenue									270,911	330,150	318,094
Operating profit									7,566,512	4,912,341	5,148,116
Assets	34,425,594				32,298,527				34,425,594	32,298,527	29,491,572
Depreciation and amortization									1,769,097	1,768,975	1,748,612
Capital expenditures									1,552,147	1,568,779	1,589,771
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									72,268,559	66,119,119	57,527,864
Assets	34,425,594				32,298,527				34,425,594	32,298,527	29,491,572
Security Products [Member]
Segment Reporting Information [Line Items]
Sales to unaffiliated customers									50,138,121	47,972,152	45,873,391
Inter-segment revenue									2,914,667	2,751,060	2,789,443
Operating profit									4,113,661	3,408,187	3,378,489
Assets	41,857,156				42,149,711				41,857,156	42,149,711	42,375,361
Depreciation and amortization									628,652	984,879	1,297,471
Capital expenditures									260,692	331,619	597,822
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									50,138,121	47,972,152	45,873,391
Assets	41,857,156				42,149,711				41,857,156	42,149,711	42,375,361
Metal Products [Member]
Segment Reporting Information [Line Items]
Sales to unaffiliated customers									35,102,505	28,764,778	26,729,105
Inter-segment revenue									0	127,138	413,408
Operating profit									1,871,250	391,652	(14,886)
Assets	18,281,619				16,814,255				18,281,619	16,814,255	15,392,848
Depreciation and amortization									1,042,051	953,362	896,556
Capital expenditures									2,337,104	1,477,222	2,438,557
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales									35,102,505	28,764,778	26,729,105
Assets	18,281,619				16,814,255				18,281,619	16,814,255	15,392,848
Operating Segments [Member]
Segment Reporting Information [Line Items]
Assets	94,564,369				91,262,493				94,564,369	91,262,493	87,259,781
Currency translation adjustment	4,216,970				3,394,726				4,216,970	3,394,726	4,733,244
Revenues from External Customers and Long-Lived Assets [Line Items]
Assets	94,564,369				91,262,493				94,564,369	91,262,493	87,259,781
General corporate [Member]
Segment Reporting Information [Line Items]
Assets	21,289,781				15,437,481				21,289,781	15,437,481	15,093,699
Currency translation adjustment	69,757				9,974				69,757	9,974	127,630
Revenues from External Customers and Long-Lived Assets [Line Items]
Assets	$ 21,289,781				$ 15,437,481				$ 21,289,781	$ 15,437,481	$ 15,093,699
Accounts Receivable [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Number of major customers									0	1
Threshold percentage of concentration risk (in hundredths)									10.00%	10.00%
Sales Revenue [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Number of major customers									0	0	0
Threshold percentage of concentration risk (in hundredths)									10.00%	10.00%	10.00%