It's been a solid year for shareholders of Ametek ( AME). The $9 billion electronic instruments company has rallied more than 28% since the first trading session in 2012. Ametek builds electronic components that range from temperature sensors to specialty motors used by original equipment manufacturers. That niche business affords AME a sticky customer base with a high switching cost, two critical factors for success in the manufacturing sector. Like other diversified industrial firms, Ametek saw significant pressure when the recession hit and factory outputs tapered off. But the firm is more than making up for it now, with revenues far surpassing pre-recession highs last year. And all the while, the firm remained handily profitable, with net margins now weighing in at more than 13.5%. Management has done an impressive job of keeping Ametek's head well above water during the roughest economic seas. While a growth-by-acquisition approach to business has been pricey for Ametek, the firm's balance sheet is strong, with over $300 million in cash and investments offsetting some of the company's $1.5 billion debt load. With AME's profitability giving the firm plenty of cash to throw at its debt, the firm is in solid shape to keep performing at a high level right now.