Inventories: Inventories (Details) - USD ($)	Mar. 31, 2019	Dec. 31, 2018
Details
Raw material	$ 3,086,524	$ 2,798,918
Work-in-process	2,289,540	1,878,977
Finished goods	2,033,395	2,001,496
Inventory, gross	7,409,459	6,679,391
Valuation reserves	(577,000)	(579,000)
Inventories, net	$ 6,832,459	$ 6,100,391

Amount before valuation and LIFO reserves of completed merchandise or goods expected to be sold within one year or operating cycle, if longer.

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Gross amount, as of the balance sheet date, of merchandise, goods, commodities, or supplies held for future sale or to be used in manufacturing, servicing or production process.

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Amount before valuation and LIFO reserves of raw materials expected to be sold, or consumed within one year or operating cycle, if longer.

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Amount before valuation and LIFO reserves of merchandise or goods in the production process expected to be completed within one year or operating cycle, if longer.

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