Segment Information (Details) - USD ($)	3 Months Ended			9 Months Ended
	Oct. 03, 2020	Sep. 28, 2019	Sep. 28, 2019	Oct. 03, 2020	Sep. 28, 2019
Revenues, sales to unaffiliated customers	$ 65,805,558	$ 60,692,645	$ 60,692,645	$ 179,964,582	$ 183,015,723
Interest expense	(647,066)	(420,377)	(420,377)	(2,081,283)	(974,536)
Other income	365,703	188,623	188,623	969,024	789,371
Income before income taxes	3,954,449	5,488,657	5,488,657	5,301,004	10,828,848
Operating Profit (loss)	4,235,812	5,720,411	$ 5,720,411	6,413,263	11,014,013
Operating Segments [Member] | Industrial Hardware [Member]
Revenues, sales to unaffiliated customers	47,141,513	39,427,301		128,249,908	115,321,597
Operating Profit (loss)	3,350,139	3,419,052		9,168,330	6,369,647
Operating Segments [Member] | Security Products [Member]
Revenues, sales to unaffiliated customers	14,189,215	14,169,694		37,687,815	45,355,397
Operating Profit (loss)	1,569,173	1,762,703		(724,125)	3,703,098
Operating Segments [Member] | Metal Products [Member]
Revenues, sales to unaffiliated customers	4,474,830	7,095,650		14,026,859	22,338,729
Operating Profit (loss)	$ (683,500)	$ 538,656		$ (2,030,942)	$ 941,268