Segment Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 29, 2018	Sep. 30, 2017	Sep. 29, 2018	Sep. 30, 2017
Segment Reporting Information [Abstract]
Revenues, sales to unaffiliated customers	$ 57,357,442	$ 56,007,937	$ 177,663,291	$ 150,095,975
Operating Profit	4,740,408	3,573,641	13,300,801	8,296,304
Interest expense	(310,507)	(327,206)	(918,897)	(659,884)
Other income	228,787	13,513	673,287	69,278
Income before income taxes	4,658,688	3,259,948	13,055,191	7,705,698
Operating Segments [Member] | Industrial Hardware [Member]
Segment Reporting Information [Abstract]
Revenues, sales to unaffiliated customers	34,210,857	32,959,599	106,621,484	83,500,656
Operating Profit	1,832,203	1,813,133	7,116,732	2,877,052
Operating Segments [Member] | Security Products [Member]
Segment Reporting Information [Abstract]
Revenues, sales to unaffiliated customers	16,918,909	16,115,356	49,926,265	46,232,410
Operating Profit	2,406,390	1,604,950	5,055,569	4,290,745
Operating Segments [Member] | Metal Products [Member]
Segment Reporting Information [Abstract]
Revenues, sales to unaffiliated customers	6,227,676	6,932,982	21,115,542	20,362,909
Operating Profit	$ 501,815	$ 155,558	$ 1,128,500	$ 1,128,507