BUSINESS SEGMENTS (Details) - Geographic information regarding net sales - USD ($)	12 Months Ended
	May 31, 2017	May 31, 2016
Net sales:
Net Sales	$ 5,791,670	$ 5,139,816
Europe [Member]
Net sales:
Net Sales	2,238,000	2,166,000
UNITED STATES
Net sales:
Net Sales	874,000	995,000
Asia [Member]
Net sales:
Net Sales	2,412,000	1,731,000
South America [Member]
Net sales:
Net Sales	65,000	67,000
Middle East [Member]
Net sales:
Net Sales	186,000	180,000
Other Foreign [Member]
Net sales:
Net Sales	$ 17,000	$ 1,000