LONGMONT - Florida-based ARC Group Worldwide Inc. (Nasdaq: ARCW) has purchased a pair of Longmont manufacturing companies, Thixoforming LLC and Advance Tooling Concepts LLC.

ARC paid $24 million for ATC, according to filings made Friday with the Securities and Exchange Commission. The purchase price for Thixoforming from its parent company - Oregon-based Precision Castparts Corp. - was not disclosed.

ARC is an advanced manufacturing and 3-D printing company, and its new acquisitions complement its offerings. ATC is a plastic injection molding company based at 33 S. Pratt Parkway that generated revenue of more than $17 million in 2013. Thixoforming is a magnesium injection molding company based at 7040 Weld County Road 20.

Officials for neither Advance Tooling nor Thixoforming could be immediately reached Monday.

"ARC's acquisition of ATC and Thixoforming provide a strategic fit within our calculated growth plan," ARC chief executive Jason Young said in a press release. "The companies add key capabilities, and accelerate our goal of being a holistic solutions provider for our customer base - from product development to prototyping to low- to high-volume production."

The purchase of Thixoforming brings that company back under the management of ARC's Colorado metal injection molding business, Advanced Forming Technology, which is located across the parking lot from Thixoforming. ARC purchased AFT from Precision Castparts last year, separating it from Thixoforming.

Cheryl Reynolds, accounting manager for ARC subsidiary Flomet, said Monday that both Thixoforming and Advance Tooling Concepts will keep their branding and continue to operate as separate companies. All employees, including ATC's executives, will be retained, Reynolds said.