Inventories

Inventories are stated at the lower of cost or market value. In the United States, we manufacture certain finished products and parts inventories for drill bits, completion products, bulk materials, and other tools that are recorded using the last-in, first-out method, which totaled $180 million as of March 31, 2014 and $157 million as of December 31, 2013. If the average cost method had been used, total inventories would have been $35 million higher than reported as of March 31, 2014 and December 31, 2013. The cost of the remaining inventory was recorded on the average cost method. Inventories consisted of the following:



Millions of dollars	March 31, 2014		December 31, 2013
Finished products and parts	$	2,509	$	2,445
Raw materials and supplies	744		720
Work in process	162		140
Total	$	3,415	$	3,305

Finished products and parts are reported net of obsolescence reserves of $134 million as of March 31, 2014 and $130 million as of December 31, 2013.