ACCOUNTING POLICIES (Details)	3 Months Ended								12 Months Ended
	Dec. 30, 2017 USD ($) shares	Sep. 30, 2017 USD ($) shares	Jul. 01, 2017 USD ($) shares	Apr. 01, 2017 USD ($) shares	Dec. 31, 2016 USD ($) shares	Oct. 01, 2016 USD ($) shares	Jul. 02, 2016 USD ($) shares	Apr. 02, 2016 USD ($) shares	Dec. 30, 2017 USD ($) Customer shares	Dec. 31, 2016 USD ($) Customer shares	Jan. 02, 2016 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 located in foreign subsidiaries									64.00%
Inventories [Abstract]
LIFO inventory amount	26,280,620								$ 26,280,620
FIFO inventory amount	8,034,924								8,034,924
Excess of current cost over LIFO carrying value	6,476,073				$ 6,121,286				6,476,073	$ 6,121,286
Property, Plant and Equipment [Line Items]
Depreciation									3,948,728	3,371,694	$ 3,460,516
Finite-Lived Intangible Assets [Line Items]
Amortization expense									770,457	442,699	460,922
Amortization expense fiscal year maturity [Abstract]
2018	1,228,000								1,228,000
2019	1,228,000								1,228,000
2020	995,000								995,000
2021	995,000								995,000
2022	853,000								853,000
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	12,910,450				4,358,510				12,910,450	4,358,510
Accumulated Amortization	3,635,292				2,594,061				3,635,292	2,594,061
Net per Balance Sheet	9,275,158				1,764,449				$ 9,275,158	$ 1,764,449
Weighted-Average Amortization Period									10 years 9 months 18 days	12 years 3 months 18 days
Goodwill [Roll Forward]
Beginning balance				$ 14,819,835				$ 14,790,793	$ 14,819,835	$ 14,790,793
Investment - Velvac									17,340,946
Foreign exchange									68,110	29,042
Ending balance	32,228,891				14,819,835				32,228,891	14,819,835	14,790,793
Engineering Costs [Abstract]
Engineering expenses	$ 1,460,670	$ 1,848,861	$ 1,682,887	$ 630,411	$ 577,056	$ 663,704	$ 733,009	$ 594,538	5,622,829	2,568,307	2,459,062
Research & development costs [Abstract]
Research & development costs									3,678,481	1,525,650	1,218,948
Advertising Costs [Abstract]
Advertising costs									$ 526,651	$ 441,853	$ 496,066
Basic [Abstract]
Weighted average shares outstanding (in shares) | shares	6,261,737	6,259,872	6,258,467	6,256,496	6,254,605	6,252,681	6,250,610	6,248,222	6,259,139	6,251,535	6,245,057
Diluted [Abstract]
Weighted average shares outstanding (in shares) | shares	6,261,737	6,259,872	6,258,467	6,256,496	6,254,605	6,252,681	6,250,610	6,248,222	6,259,139	6,251,535	6,245,057
Dilutive stock options (in shares) | shares									35,634	0	0
Denominator for diluted earnings per share (in shares) | shares	6,297,371	6,296,551	6,285,339	6,256,496	6,254,605	6,252,681	6,250,610	6,248,222	6,294,773	6,251,535	6,245,057
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	$ 10,724,456				$ 2,159,060				$ 10,724,456	$ 2,159,060
Accumulated Amortization	2,306,063				1,529,675				2,306,063	1,529,675
Net per Balance Sheet	8,418,393				629,385				8,418,393	629,385
Goodwill [Roll Forward]
Beginning balance				$ 1,760,793				$ 1,731,751	1,760,793	1,731,751
Investment - Velvac									17,340,946
Foreign exchange									68,110	29,042
Ending balance	19,169,849				1,760,793				19,169,849	1,760,793	$ 1,731,751
Security Products Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	2,185,994				2,199,450				2,185,994	2,199,450
Accumulated Amortization	1,329,229				1,064,386				1,329,229	1,064,386
Net per Balance Sheet	856,765				1,135,064				856,765	1,135,064
Goodwill [Roll Forward]
Beginning balance				13,059,042				13,059,042	13,059,042	13,059,042
Investment - Velvac									0
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
Investment - Velvac									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	8,096,374				3,194,434				$ 8,096,374	3,194,434
Accumulated Amortization	2,638,202				2,128,431				$ 2,638,202	$ 2,128,431
Weighted-Average Amortization Period									12 years 3 months 18 days	15 years 7 months 6 days
Patents and Developed Technology [Member] | Industrial Hardware Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	7,074,456				2,159,060				$ 7,074,456	$ 2,159,060
Accumulated Amortization	2,007,418				1,529,675				2,007,418	1,529,675
Patents and Developed Technology [Member] | Security Products Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	1,021,918				1,035,374				1,021,918	1,035,374
Accumulated Amortization	630,784				598,756				630,784	598,756
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	4,099,706				449,706				$ 4,099,706	449,706
Accumulated Amortization	568,468				179,882				$ 568,468	$ 179,882
Weighted-Average Amortization Period									9 years 6 months	5 years
Customer Relationships [Member] | Industrial Hardware Segment [Member]
Gross carrying amount and accumulated amortization of amortizable intangible assets [Abstract]
Gross Amount	3,650,000				0				$ 3,650,000	$ 0
Accumulated Amortization	298,645				0				298,645	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	269,823				179,882				269,823	179,882
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	244,200				162,800				$ 244,200	$ 162,800
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	244,200				162,800				244,200	162,800
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	184,422				122,948				$ 184,422	$ 122,948
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	184,422				122,948				184,422	122,948
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									25,000	0	0
Stock Appreciation Rights (SARs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares) | shares									149,500	0
Stock Options and SARs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted (in shares) | shares									174,500