Geographic Information (Details) - Financial information about foreign and domestic operations and export sales - USD ($)	3 Months Ended
	Aug. 31, 2016	Aug. 31, 2015
Revenues from sales to unaffiliated customers:
Net Sales	$ 1,410,110	$ 1,286,993
UNITED STATES
Revenues from sales to unaffiliated customers:
Net Sales	226,000	187,000
Asia [Member]
Revenues from sales to unaffiliated customers:
Net Sales	575,000	433,000
Europe [Member]
Revenues from sales to unaffiliated customers:
Net Sales	554,000	619,000
South America [Member]
Revenues from sales to unaffiliated customers:
Net Sales	16,000	17,000
Middle East [Member]
Revenues from sales to unaffiliated customers:
Net Sales	38,000	31,000
Other Foreign [Member]
Revenues from sales to unaffiliated customers:
Net Sales	$ 1,000