Segment Information (Details) (USD $)	3 Months Ended		6 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Mar. 31, 2012
Segment information, reportable segments
Net sales	$ 33,334,070	$ 42,039,282	$ 72,768,840	$ 80,974,738
Operating profit	3,010,000	4,196,000	7,050,000	7,783,000
Interest & other income	(16,000)	(15,000)	(28,000)	(33,000)
Total earnings before taxes	2,470,000	3,475,000	5,570,000	6,230,000
Total assets	76,281,931		76,281,931		78,570,393
Coil [Member]
Segment information, reportable segments
Net sales	16,722,000	15,710,000	33,552,000	31,140,000
Operating profit	274,000	329,000	628,000	0
Total assets	22,611,000		22,611,000		26,260,000
Tubular [Member]
Segment information, reportable segments
Net sales	16,612,000	26,330,000	39,217,000	49,835,000
Operating profit	2,736,000	3,867,000	6,422,000	7,783,000
Total assets	31,977,000		31,977,000		39,446,000
Operating Segments [Member]
Segment information, reportable segments
Total assets	54,588,000		54,588,000		65,706,000
Corporate [Member]
Segment information, reportable segments
Corporate expenses	556,000	736,000	1,508,000	1,586,000
Total assets	$ 21,694,000		$ 21,694,000		$ 12,864,000