Inventories

Inventories at December 31, 2015 and 2014 were as follows (in millions):



	2015			2014
Raw materials and supplies	$	216.0		$	249.3
Work-in-process	990.3			1,184.1
Finished goods	184.1			172.2
Total inventories at current cost	1,390.4			1,605.6
Adjustment from current cost to LIFO cost basis	136.4			4.8
Inventory valuation reserves	(206.3		)	(68.8		)
Progress payments	(48.9		)	(68.8		)
Total inventories, net	$	1,271.6		$	1,472.8

Inventories, before progress payments, determined on the LIFO method were $992.0 million at December 31, 2015, and $1,102.4 million at December 31, 2014. The remainder of the inventory was determined using the FIFO and average cost methods, and these inventory values do not differ materially from current cost. Due to deflationary impacts primarily related to raw materials, the carrying value of the Company’s inventory as valued on the LIFO inventory accounting method exceeded current replacement cost initially as of December 31, 2013, and based on a lower of cost or market value analysis, a net realizable value (NRV) inventory reserve was recorded. In applying the lower of cost or market principle, market means current replacement cost, subject to a ceiling (market value shall not exceed net realizable value) and a floor (market shall not exceed net realizable value reduced by an allowance for a normal profit margin). Impacts to cost of sales for changes in the LIFO costing methodology and associated NRV reserves were as follows (in millions):



	Fiscal year ended December 31,
	2015			2014			2013
LIFO benefit (charge)	$	131.6		$	(24.7	)	$	80.9
NRV benefit (charge)	$	(131.5	)	$	25.0		$	(35.0	)
Net cost of sales impact	$	0.1		$	0.3		$	45.9

During 2015 and 2013, inventory usage resulted in liquidations of LIFO inventory quantities, increasing cost of sales by $9.6 million and $3.8 million in 2015 and 2013, respectively. These inventories were carried at differing costs prevailing in prior years as compared with the cost of current manufacturing cost and purchases. There were no LIFO liquidations in 2014.

The Company also recorded lower of cost or market charges primarily related to non-premium quality (PQ) grade products during the ramp-up and qualification of the Rowley, UT titanium sponge production facility and continued sluggish demand for industrial titanium products from global markets. These lower of cost or market charges were $24.5 million in 2015, $23.2 million in 2014 and $20.5 million in 2013. Additionally, in December 2015, based on current market prices for non-PQ grades of titanium sponge, the Company recorded a $25.4 million charge to revalue this inventory. This charge includes revised assessments of the non-PQ titanium market conditions and expected utilization of this inventory.