Note K - Revenue - Disaggregation of Revenue (Details) - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Net Sales	$ 24,861,680	$ 39,995,580	$ 48,386,280	$ 80,970,900
Coil [Member]
Net Sales	18,456,086	28,420,609	33,888,870	56,602,077
Coil [Member] | Prime Coil [Member]
Net Sales	17,049,230	24,936,635	30,356,698	49,165,088
Coil [Member] | Secondary Coil [Member]
Net Sales	1,201,135	3,271,453	3,142,138	7,043,968
Coil [Member] | Customer Owned [Member]
Net Sales	205,721	212,521	390,034	393,021
Tubular [Member]
Net Sales	6,405,594	11,574,971	14,497,410	24,368,823
Tubular [Member] | Manufactured Pipe [Member]
Net Sales	5,296,334	9,744,189	12,458,184	20,476,676
Tubular [Member] | Mill Reject Pipe [Member]
Net Sales	$ 1,109,260	$ 1,830,782	$ 2,039,226	$ 3,892,147