Firth Rixson products include jet engine parts like turbine and compressor cases. The company brought in $1 billion in revenue last year, mostly from the aerospace industry, and sales are expected to grow 12 percent annually through 2019, according to Alcoa.
The high cost of producing aluminum and falling prices for the metal have hurt Alcoa Inc. and pushed it toward more finished products that are used in aircraft, autos and other goods.
In April, the company reported quarterly losses of $178 million. Aluminum prices haven't recovered since the recession and Alcoa has been idling smelters to reduce capacity and cut costs.
At the same time, Alcoa is shifting sideways toward components.
The company last month revealed that it would spend $100 million to build factory in Indiana to make nickel-based engine parts for commercial airliners. With fuel prices rising, demand for more fuel-efficient planes has soared. Alcoa has said it expects the aerospace industry to grow by 8 percent to 9 percent this year.
The Firth Rixson deal will help raise Alcoa's aerospace profile, according to Sterne Agee analyst Josh Sullivan.
"We continue to believe Alcoa's strong aerospace positioning is underappreciated," Sullivan wrote.
Automakers, too, want to lighten up.
Around 30 percent of new vehicles are now rolling off the production line with aluminum hoods. Ford has unveiled an aluminum-body 2015 F-150 pickup that has all the power of the original, but weighs up to 700 pounds less. The truck goes on sale later this year.
The boards of directors for both companies have approved the Firth Rixson deal, which is expected to close by the end of this year.
Shares of Alcoa climbed 63 cents to $15.18 at the start of trading Thursday, topping $15 for the first time since the summer of 2011.
Last fall, the Dow Jones industrial average dropped Alcoa due partly to its sagging stock price.