Segment Reporting: Schedule of Segment Reporting, by Segment (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Net sales	$ 7,576,455	$ 8,621,678
Depreciation	337,356	336,389
Accounts receivable - Less allowances of $155,000 and $140,000, respectively	5,503,683		$ 4,609,314
Inventories, net	5,178,381		4,951,177
Net property, plant and equipment	13,504,694		$ 13,674,053
Fastener
Net sales	6,737,397	7,579,120
Depreciation	296,110	297,723
Segment operating profit	404,018	588,895
Selling and administrative expenses	0	0
Interest income	0	0
Capital expenditures	167,997	756,107
Accounts receivable - Less allowances of $155,000 and $140,000, respectively	5,106,941	5,500,631
Inventories, net	4,195,183	5,831,166
Net property, plant and equipment	10,919,327	11,184,576
Other Assets	0	0
Assembly Equipment
Net sales	839,058	1,042,558
Depreciation	32,869	28,924
Segment operating profit	184,571	336,074
Selling and administrative expenses	0	0
Interest income	0	0
Capital expenditures	0	124,000
Accounts receivable - Less allowances of $155,000 and $140,000, respectively	396,742	453,843
Inventories, net	983,198	1,001,293
Net property, plant and equipment	1,653,895	1,674,573
Other Assets	0	0
Unallocated Corporate
Net sales	0	0
Depreciation	8,377	9,742
Segment operating profit	0	0
Selling and administrative expenses	(550,896)	(593,402)
Interest income	33,875	36,275
Capital expenditures	0	26,025
Accounts receivable - Less allowances of $155,000 and $140,000, respectively	0	0
Inventories, net	0	0
Net property, plant and equipment	931,472	968,740
Other Assets	$ 7,619,802	$ 6,192,967