ACCOUNTING POLICIES (Details)	3 Months Ended								12 Months Ended
	Dec. 31, 2016 USD ($) shares	Oct. 01, 2016 shares	Jul. 02, 2016 shares	Apr. 02, 2016 USD ($) shares	Jan. 02, 2016 USD ($) shares	Oct. 03, 2015 shares	Jul. 04, 2015 shares	Apr. 04, 2015 USD ($) shares	Dec. 31, 2016 USD ($) Customer shares	Jan. 02, 2016 USD ($) Customer shares	Jan. 03, 2015 USD ($) Customer shares
Cash Equivalents and Concentrations of Credit Risk [Abstract]
Amount of deposits insured by Federal Deposit Insurance Corporation (FDIC)	$ 250,000								$ 250,000
Percentage of available cash									51.00%
Inventories [Abstract]
LIFO inventory amount	28,052,368								$ 28,052,368
FIFO inventory amount	5,977,918								5,977,918
Excess of current cost over LIFO carrying value	6,121,286				$ 6,297,368				6,121,286	$ 6,297,368
Property, Plant and Equipment [Line Items]
Depreciation									3,371,694	3,460,516	$ 3,237,426
Finite-Lived Intangible Assets [Line Items]
Amortization expense									442,699	460,922	248,876
Amortization expense fiscal year maturity [Abstract]
2017	406,000								406,000
2018	406,000								406,000
2019	406,000								406,000
2020	173,000								173,000
2021	147,000								147,000
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	4,358,510				4,400,109				4,358,510	4,400,109
Accumulated Amortization	2,594,061				2,286,533				2,594,061	2,286,533
Net per Balance Sheet	1,764,449				2,113,576				$ 1,764,449	$ 2,113,576
Weighted-Average Amortization Period									12 years 3 months 18 days	12 years 7 months 6 days
Goodwill [Roll Forward]
Beginning balance				$ 14,790,793				$ 14,960,354	$ 14,790,793	$ 14,960,354
Foreign exchange									29,042	(169,561)
Ending balance	$ 14,819,835				$ 14,790,793				14,819,835	14,790,793	14,960,354
Research & development costs [Abstract]
Research & development costs									1,525,650	1,218,948	1,079,557
Advertising Costs [Abstract]
Advertising costs									$ 441,853	$ 496,066	$ 494,267
Basic [Abstract]
Weighted average shares outstanding (in shares) | shares	6,254,605	6,252,681	6,250,610	6,248,222	6,246,571	6,245,099	6,244,051	6,244,088	6,251,535	6,245,057	6,225,068
Diluted [Abstract]
Weighted average shares outstanding (in shares) | shares	6,254,605	6,252,681	6,250,610	6,248,222	6,246,571	6,245,099	6,244,051	6,244,088	6,251,535	6,245,057	6,225,068
Dilutive stock options (in shares) | shares									0	0	12,846
Denominator for diluted earnings per share (in shares) | shares	6,254,605	6,252,681	6,250,610	6,248,222	6,246,571	6,245,099	6,244,051	6,244,088	6,251,535	6,245,057	6,237,914
Anti-dilutive stock options (in shares) | shares									0	0	0
Industrial Hardware Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	$ 2,159,060				$ 2,206,852				$ 2,159,060	$ 2,206,852
Accumulated Amortization	1,529,675				1,478,692				1,529,675	1,478,692
Net per Balance Sheet	629,385				728,160				629,385	728,160
Goodwill [Roll Forward]
Beginning balance				$ 1,731,751				$ 1,901,312	1,731,751	1,901,312
Foreign exchange									29,042	(169,561)
Ending balance	1,760,793				1,731,751				1,760,793	1,731,751	$ 1,901,312
Security Products Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	2,199,450				2,193,257				2,199,450	2,193,257
Accumulated Amortization	1,064,386				807,841				1,064,386	807,841
Net per Balance Sheet	1,135,064				1,385,416				1,135,064	1,385,416
Goodwill [Roll Forward]
Beginning balance				13,059,042				13,059,042	13,059,042	13,059,042
Foreign exchange									0	0
Ending balance	13,059,042				13,059,042				13,059,042	13,059,042	13,059,042
Metal Products Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	0				0				0	0
Accumulated Amortization	0				0				0	0
Net per Balance Sheet	0				0				0	0
Goodwill [Roll Forward]
Beginning balance				$ 0				$ 0	0	0
Foreign exchange									0	0
Ending balance	0				0				$ 0	0	$ 0
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
Technology and Licenses [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful lives of intangible assets									5 years
Technology and Licenses [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Useful lives of intangible assets									17 years
Patents and Developed Technology [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	3,194,434				3,236,033				$ 3,194,434	3,236,033
Accumulated Amortization	2,128,431				2,053,718				$ 2,128,431	$ 2,053,718
Weighted-Average Amortization Period									15 years 7 months 6 days	15 years 10 months 24 days
Patents and Developed Technology [Member] | Industrial Hardware Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	2,159,060				2,206,852				$ 2,159,060	$ 2,206,852
Accumulated Amortization	1,529,675				1,478,692				1,529,675	1,478,692
Patents and Developed Technology [Member] | Security Products Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	1,035,374				1,029,181				1,035,374	1,029,181
Accumulated Amortization	598,756				575,026				598,756	575,026
Patents and Developed Technology [Member] | Metal Products Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	0				0				0	0
Accumulated Amortization	0				0				$ 0	0
Customer Relationships [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	449,706				449,706				$ 449,706	449,706
Accumulated Amortization	179,882				89,941				$ 179,882	$ 89,941
Weighted-Average Amortization Period									5 years	5 years
Customer Relationships [Member] | Industrial Hardware Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	0				0				$ 0	$ 0
Accumulated Amortization	0				0				0	0
Customer Relationships [Member] | Security Products Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	449,706				449,706				449,706	449,706
Accumulated Amortization	179,882				89,941				179,882	89,941
Customer Relationships [Member] | Metal Products Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	0				0				0	0
Accumulated Amortization	0				0				$ 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	407,000				407,000				$ 407,000	407,000
Accumulated Amortization	162,800				81,400				$ 162,800	$ 81,400
Weighted-Average Amortization Period									5 years	5 years
Non-Compete Agreements [Member] | Industrial Hardware Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	0				0				$ 0	$ 0
Accumulated Amortization	0				0				0	0
Non-Compete Agreements [Member] | Security Products Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	407,000				407,000				407,000	407,000
Accumulated Amortization	162,800				81,400				162,800	81,400
Non-Compete Agreements [Member] | Metal Products Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	0				0				0	0
Accumulated Amortization	0				0				0	0
Intellectual Property [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	307,370				307,370				307,370	307,370
Accumulated Amortization	122,948				61,474				$ 122,948	$ 61,474
Weighted-Average Amortization Period									5 years	5 years
Intellectual Property [Member] | Industrial Hardware Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	0				0				$ 0	$ 0
Accumulated Amortization	0				0				0	0
Intellectual Property [Member] | Security Products Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	307,370				307,370				307,370	307,370
Accumulated Amortization	122,948				61,474				122,948	61,474
Intellectual Property [Member] | Metal Products Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	0				0				0	0
Accumulated Amortization	$ 0				$ 0				$ 0	$ 0
Sales Revenue, Net [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Number of major customers | Customer									0	0	0
Accounts Receivable [Member] | Customer Concentration Risk [Member]
Concentration Risk [Line Items]
Number of major customers | Customer									0	0
Threshold percentage of concentration risk									10.00%	10.00%
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares) | shares									0	0	0