Segments

The Company operates through three reportable segments: Supply Technologies, Assembly Components and Engineered Products. Supply Technologies provides our customers with Total Supply Management™ services for a broad range of high-volume, specialty production components. Assembly Components manufactures cast aluminum components, automotive and industrial rubber and thermoplastic products, gasoline direct injection systems, fuel filler and hydraulic assemblies for automotive, agricultural equipment, construction equipment, heavy-duty truck and marine equipment industries, and also provides value-added services such as design and engineering, machining and assembly. Engineered Products operates a diverse group of niche manufacturing businesses that design and manufacture a broad range of high quality products engineered for specific customer applications.

For purposes of measuring business segment performance, the Company utilizes segment operating income, which is defined as revenues less expenses identifiable to the product lines within each segment. The Company does not allocate items that are non-operating; unusual in nature; or are corporate costs, which include but are not limited to executive compensation and corporate office costs. Segment operating income reconciles to consolidated income before income taxes by deducting corporate costs, certain non-cash charges and interest expense.

Results by business segment were as follows:



	Year Ended December 31,
	2017			2016			2015
	(In millions)
Net sales:
Supply Technologies	$	561.8		$	502.1		$	578.7
Assembly Components	524.5			529.4			569.2
Engineered Products	326.6			245.4			315.9
	$	1,412.9		$	1,276.9		$	1,463.8
Segment operating income:
Supply Technologies	$	45.9		$	40.0		$	50.3
Assembly Components	50.4			50.5			57.9
Engineered Products	20.7			10.6			20.9
Total segment operating income	117.0			101.1			129.1
Corporate costs	(30.1		)	(27.9		)	(29.0		)
Asset impairment charge	—			(4.0		)	—
Litigation settlement gains (judgment costs)	3.3			—			(2.2		)
Operating income	90.2			69.2			97.9
Interest expense	(31.5		)	(28.2		)	(27.9		)
Loss on extinguishment of debt	(11.0		)	—			—
Income before income taxes	$	47.7		$	41.0		$	70.0



	Year Ended December 31,
	2017		2016		2015
	(In millions)
Capital expenditures:
Supply Technologies	$	3.3	$	6.1	$	3.7
Assembly Components	18.6		16.9		27.3
Engineered Products	5.7		5.5		5.5
Corporate	0.3		—		—
	$	27.9	$	28.5	$	36.5
Depreciation and amortization expense:
Supply Technologies	$	4.7	$	4.7	$	4.7
Assembly Components	20.7		20.1		18.6
Engineered Products	5.6		4.1		4.2
Corporate	0.5		0.6		1.2
	$	31.5	$	29.5	$	28.7
Identifiable assets:
Supply Technologies	$	344.4	$	262.0	$	276.3
Assembly Components	351.4		332.9		344.8
Engineered Products	353.6		304.9		243.1
Corporate	83.1		74.5		77.9
	$	1,132.5	$	974.3	$	942.1

The percentage of net sales by product line included in each segment was as follows:



	Year Ended December 31,
	2017		2016		2015
Supply Technologies:
Supply Technologies	85	%	85	%	87	%
Engineered specialty products	15	%	15	%	13	%
	100	%	100	%	100	%
Assembly Components:
Fuel-related, rubber and plastic products	70	%	67	%	59	%
Aluminum products	30	%	33	%	41	%
	100	%	100	%	100	%
Engineered Products:
Industrial equipment business	84	%	79	%	81	%
Forged and machined products	16	%	21	%	19	%
	100	%	100	%	100	%

The Company’s approximate percentage of net sales by geographic region was as follows:



	Year Ended December 31,
	2017		2016		2015
United States	65	%	71	%	72	%
Europe	10	%	8	%	7	%
Asia	9	%	8	%	8	%
Mexico	8	%	6	%	6	%
Canada	7	%	6	%	6	%
Other	1	%	1	%	1	%
	100	%	100	%	100	%

The basis for attributing revenue to individual geographic regions is customer location.

At December 31, 2017, 2016 and 2015, approximately 65%, 68% and 71%, respectively, of the Company’s assets were located in the United States.