Inventories (Tables)

3 Months Ended

Jul. 31, 2017

Inventory, Net [Abstract]

Components of Inventories

The components of inventories were: 

	July 31,			April 30,
(in thousands)	2017			2017
Raw materials	$	20,195		$	18,230
Work-in-process	18,283			18,704
Finished goods	19,446			19,372
Total FIFO inventories	57,924			56,306
Reserve to adjust inventories to LIFO value	(13,447		)	(13,447		)
Total LIFO inventories	$	44,477		$	42,859