Accounting Policies (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
Cash Equivalents and Concentrations of Credit Risk [Abstract]
Amount of deposits insured by Federal Deposit Insurance Corporation (FDIC)	$ 250,000								$ 250,000
Inventory [Abstract]
LIFO inventory amount	21,580,351								21,580,351
FIFO inventory amount	7,804,429								7,804,429
Excess of current cost over LIFO carrying value	6,302,000				6,281,000				6,302,000	6,281,000
Property, Plant and Equipment [Line Items]
Depreciation									3,210,324	3,155,717	3,265,832
Finite-Lived Intangible Assets [Line Items]
Amortization expense									229,476	551,499	676,807
Amortization expense fiscal year maturity [Abstract]
2013	215,000								215,000
2014	215,000								215,000
2015	215,000								215,000
2016	215,000								215,000
2017	215,000								215,000
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	3,759,555				5,871,762				3,759,555	5,871,762
Accumulated Amortization	2,105,598				4,101,754				2,105,598	4,101,754
Net per Balance Sheet	1,653,957				1,770,008				1,653,957	1,770,008
Weighted-Average Amortization Period									15 years 9 months 18 days	11 years 8 months 12 days
Goodwill [Roll Forward]
Beginning balance				13,905,209				13,933,990	13,905,209	13,933,990
Foreign exchange									28,390	(28,781)
Ending balance	13,933,599				13,905,209				13,933,599	13,905,209	13,933,990
Product development costs [Abstract]
Product development costs									814,096	825,778	739,251
Advertising costs [Abstract]
Advertising costs									442,300	386,908	446,899
Basic [Abstract]
Weighted average shares outstanding (in shares)	6,219,384	6,219,241	6,217,198	6,213,913	6,212,875	6,172,193	6,166,883	6,162,711	6,216,931	6,178,664	6,104,711
Diluted [Abstract]
Weighted average shares outstanding (in shares)	6,219,384	6,219,241	6,217,198	6,213,913	6,212,875	6,172,193	6,166,883	6,162,711	6,216,931	6,178,664	6,104,711
Dilutive stock options (in shares)									16,444	37,529	87,308
Denominator for diluted earnings per share (in shares)	6,237,709	6,234,727	6,231,335	6,231,739	6,230,722	6,202,496	6,218,492	6,213,069	6,233,375	6,216,193	6,192,019
Anti-dilutive stock options (in shares)									0	0	0
Industrial Hardware Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	2,732,307				2,790,725				2,732,307	2,790,725
Accumulated Amortization	1,652,199				1,588,667				1,652,199	1,588,667
Net per Balance Sheet	1,080,108				1,202,058				1,080,108	1,202,058
Goodwill [Roll Forward]
Beginning balance				2,071,393				2,100,174	2,071,393	2,100,174
Foreign exchange									28,390	(28,781)
Ending balance	2,099,783				2,071,393				2,099,783	2,071,393
Security Products Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	1,021,409				3,075,198				1,021,409	3,075,198
Accumulated Amortization	447,732				2,507,764				447,732	2,507,764
Net per Balance Sheet	573,677				567,434				573,677	567,434
Goodwill [Roll Forward]
Beginning balance				11,833,816				11,833,816	11,833,816	11,833,816
Foreign exchange									0	0
Ending balance	11,833,816				11,833,816				11,833,816	11,833,816
Metal Products Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	5,839				5,839				5,839	5,839
Accumulated Amortization	5,667				5,323				5,667	5,323
Net per Balance Sheet	172				516				172	516
Goodwill [Roll Forward]
Beginning balance				0				0	0	0
Foreign exchange									0	0
Ending balance	0				0				0	0
Patents and Developed Technology [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount					3,783,391					3,783,391
Accumulated Amortization					2,028,548					2,028,548
Weighted-Average Amortization Period										15 years 6 months
Patents and Developed Technology [Member] | Industrial Hardware Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount					2,714,900					2,714,900
Accumulated Amortization					1,528,007					1,528,007
Patents and Developed Technology [Member] | Security Products Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount					1,062,652					1,062,652
Accumulated Amortization					495,218					495,218
Patents and Developed Technology [Member] | Metal Products Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount					5,839					5,839
Accumulated Amortization					5,323					5,323
Customer Relationships [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount					1,967,636					1,967,636
Accumulated Amortization					1,958,471					1,958,471
Weighted-Average Amortization Period										5 years
Customer Relationships [Member] | Industrial Hardware Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount					45,825					45,825
Accumulated Amortization					36,660					36,660
Customer Relationships [Member] | Security Products Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount					1,921,811					1,921,811
Accumulated Amortization					1,921,811					1,921,811
Customer Relationships [Member] | Metal Products Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount					0					0
Accumulated Amortization					0					0
Non-Compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Useful lives of intangible assets									5 years
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount					120,735					120,735
Accumulated Amortization					114,735					114,735
Weighted-Average Amortization Period										5 years
Non-Compete Agreements [Member] | Industrial Hardware Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount					30,000					30,000
Accumulated Amortization					24,000					24,000
Non-Compete Agreements [Member] | Security Products Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount					90,735					90,735
Accumulated Amortization					90,735					90,735
Non-Compete Agreements [Member] | Metal Products Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount					0					0
Accumulated Amortization					$ 0					$ 0
Minimum [Member] | Technology and Licenses [Member]
Finite-Lived Intangible Assets [Line Items]
Useful lives of intangible assets									5 years
Maximum [Member] | Technology and Licenses [Member]
Finite-Lived Intangible Assets [Line Items]
Useful lives of intangible assets									17 years
Building [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of the assets									10 years
Building [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of the assets									39 years 6 months
Machinery and Equipment [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of the assets									3 years
Machinery and Equipment [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Estimated useful lives of the assets									10 years
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%