Segments

Our operating segments are defined as components of the enterprise for which separate financial information is available and evaluated on a regular basis by our chief operating decision maker to allocate resources and assess performance.

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 and share-based compensation and corporate office costs. Segment operating income reconciles to consolidated income before income taxes by deducting corporate costs, certain non-cash items, other components of net pension income and interest expense.

Results by business segment were as follows:



	Three Months Ended March 31,
	2018			2017
	(In millions)
Net sales:
Supply Technologies	$	160.9		$	133.2
Assembly Components	145.4			139.3
Engineered Products	99.4			71.3
	$	405.7		$	343.8
Segment operating income:
Supply Technologies	$	12.5		$	10.6
Assembly Components	12.6			11.8
Engineered Products	5.7			1.3
Total segment operating income	30.8			23.7

Corporate costs	(8.7		)	(6.5		)
Litigation settlement gain	—			3.3
Operating income	22.1			20.5
Other components of net pension income	2.3			1.7
Interest expense	(8.4		)	(7.4		)
Income before income taxes	$	16.0		$	14.8