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 and/or non-operating items; Other components of pension income and other postretirement benefits (“OPEB”) expense, net; and interest expense.

Results by business segment were as follows:



	Year Ended December 31,
	2018			2017			2016
Net sales:
Supply Technologies	$	636.8		$	561.8		$	502.1
Assembly Components	578.3			524.5			529.4
Engineered Products	443.0			326.6			245.4
	$	1,658.1		$	1,412.9		$	1,276.9
Segment operating income:
Supply Technologies	$	49.0		$	43.3		$	37.5
Assembly Components	42.9			47.8			48.0
Engineered Products	38.4			19.5			9.4
Total segment operating income	130.3			110.6			94.9
Corporate costs	(34.9		)	(30.1		)	(27.9		)
Gain on sale of assets	1.9			—			—
Litigation settlement gain	—			3.3			—
Asset impairment charge	—			—			(4.0		)
Operating income	97.3			83.8			63.0
Other components of pension income and other postretirement benefits expense, net	8.8			6.4			6.2
Interest expense, net	(34.3		)	(31.5		)	(28.2		)
Loss on extinguishment of debt	—			(11.0		)	—
Income before income taxes	$	71.8		$	47.7		$	41.0



	Year Ended December 31,
	2018		2017		2016
Capital expenditures:
Supply Technologies	$	5.2	$	3.3	$	6.1
Assembly Components	24.3		18.6		16.9
Engineered Products	15.4		5.7		5.5
Corporate	0.2		0.3		—
	$	45.1	$	27.9	$	28.5
Depreciation and amortization expense:
Supply Technologies	$	5.3	$	4.7	$	4.7
Assembly Components	22.2		20.7		20.1
Engineered Products	8.4		5.6		4.1
Corporate	0.4		0.5		0.6
	$	36.3	$	31.5	$	29.5
Identifiable assets:
Supply Technologies	$	330.1	$	344.4	$	262.0
Assembly Components	378.3		351.4		332.9
Engineered Products	433.1		353.6		304.9
Corporate	67.0		83.1		74.5
	$	1,208.5	$	1,132.5	$	974.3

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



	Year Ended December 31,
	2018		2017		2016
Supply Technologies:
Supply Technologies	87	%	85	%	85	%
Engineered specialty products	13	%	15	%	15	%
	100	%	100	%	100	%
Assembly Components:
Fuel-related, rubber and plastic products	66	%	70	%	67	%
Aluminum products	34	%	30	%	33	%
	100	%	100	%	100	%
Engineered Products:
Industrial equipment business	70	%	84	%	79	%
Forged and machined products	30	%	16	%	21	%
	100	%	100	%	100	%

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



	Year Ended December 31,
	2018		2017		2016
United States	66	%	65	%	71	%
Europe	11	%	10	%	8	%
Asia	8	%	9	%	8	%
Mexico	6	%	8	%	6	%
Canada	8	%	7	%	6	%
Other	1	%	1	%	1	%
	100	%	100	%	100	%

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

At December 31, 2018, 2017 and 2016, approximately 68%, 65% and 68%, respectively, of the Company’s assets were located in the United States.