Note E - Segment Information - Segment Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Mar. 31, 2016
Net sales	$ 15,988,745	$ 18,548,247	$ 56,700,015	$ 65,682,520
Interest & other income	(14,755)	(328,560)	(44,255)	(363,060)
Total earnings (loss) before taxes	(370,979)	696,167	(3,648,757)	1,213,971
Assets	63,580,354		63,580,354		$ 66,890,397
Operating Segments [Member]
Operating profit (loss)	101,000	840,000	(2,218,000)	2,534,000
Assets	55,082,000		55,082,000		62,860,000
Operating Segments [Member] | Coil [Member]
Net sales	13,495,000	15,203,000	47,945,000	52,838,000
Operating profit (loss)	538,000	1,817,000	(858,000)	4,858,000
Assets	17,545,000		17,545,000		25,317,000
Operating Segments [Member] | Tubular [Member]
Net sales	2,494,000	3,345,000	8,755,000	12,845,000
Operating profit (loss)	(437,000)	(977,000)	(1,360,000)	(2,324,000)
Assets	37,537,000		37,537,000		37,543,000
Corporate, Non-Segment [Member]
Corporate expenses	487,000	$ 473,000	1,475,000	$ 1,683,000
Assets	$ 8,498,000		$ 8,498,000		$ 4,030,000