Inventories

Inventories consisted of the following components as of December 31, 2018 and June 30, 2018:



($ in millions)	December 31, 2018		June 30, 2018
Raw materials and supplies	$	177.3	$	157.5
Work in process	465.0		372.5
Finished and purchased products	201.9		159.2
Total inventory	$	844.2	$	689.2

Inventories are valued at the lower of cost or market. Cost for inventories is principally determined using the last-in, first-out (“LIFO”) inventory costing method. The Company also uses the first-in, first-out (“FIFO”) and average cost methods. As of December 31, 2018 and June 30, 2018, $181.3 million and $138.6 million of inventory, respectively, was accounted for using a method other than the LIFO inventory costing method.