Inventories (Tables)

3 Months Ended

Jul. 31, 2018

Inventory, Net [Abstract]

Components of Inventories

The components of inventories were: 

	July 31,			April 30,
(in thousands)	2018			2018
Raw materials	$	45,737		$	41,728
Work-in-process	47,192			44,905
Finished goods	36,561			34,111
Total FIFO inventories	129,490			120,744
Reserve to adjust inventories to LIFO value	(15,943		)	(15,943		)
Total inventories	$	113,547		$	104,801