Segment Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Mar. 31, 2013
Segment Reporting Information [Line Items]
Net sales	$ 26,310,369	$ 33,334,070	$ 55,892,512	$ 72,768,840
Operating profit (loss)	407,000	3,010,000	2,235,000	7,050,000
Interest & other income	(16,000)	(16,000)	(31,000)	(28,000)
Total earnings before taxes	47,757	2,469,776	1,202,206	5,569,905
Total assets	72,926,473		72,926,473		76,575,129
Coil
Segment Reporting Information [Line Items]
Net sales	14,678,000	16,722,000	31,841,000	33,552,000
Operating profit (loss)	(700,000)	274,000	(522,000)	628,000
Total assets	25,363,000		25,363,000		29,780,000
Tubular
Segment Reporting Information [Line Items]
Net sales	11,632,000	16,612,000	24,052,000	39,217,000
Operating profit (loss)	1,107,000	2,736,000	2,757,000	6,422,000
Total assets	32,508,000		32,508,000		29,834,000
Corporate
Segment Reporting Information [Line Items]
Corporate expenses	375,000	556,000	1,064,000	1,508,000
Total assets	15,055,000		15,055,000		16,961,000
Operating Segments
Segment Reporting Information [Line Items]
Total assets	$ 57,871,000		$ 57,871,000		$ 59,614,000