Midwest Manufacturing News • March 2026 • PTG Holroyd Precision Rotors Increases Blower Screw Manufacturing Capability

PTG Holroyd Precision Rotors, the specialist helical component, screw, and rotor manufacturing division of Precision Technologies Group (PTG), has increased the capacity of its positive-displacement blower screw production line at its facility in Spartanburg, SC.

Opened in 2018 to provide North America’s leading manufacturers of industrial air equipment, air conditioning and refrigeration equipment with precise helical components, the Spartanburg site was the result of a significant investment by Precision Technologies Group.

This latest investment at Spartanburg by PTG is in response to a 30% increase in blower screw sales year on year. It will enable the Holroyd team to pursue additional new business opportunities and further satisfy the growing demand across the United States for the helical screws that are used in conventional straight-fluted, infinite lead Roots-type rotary lobe blowers, twin-screw blowers, and oilfree screw compressors.

“Manufactured to the tightest of tolerances, our energy efficient screw blowers, twin-screw helical blowers, and oil-free compressor screws are renowned across sectors as wide-ranging as food & drink, dry bulk materials handling, pharmaceuticals, power generation, pulp, paper, and petrochemicals,” said Colin Carr, Managing Director, PTG Holroyd Precision Rotors.

“The increase in capability at Spartanburg means we are now able to manufacture an additional 25% volume precision screw sets per week on a single shift, with the option to operate multiple shifts 24/7 whenever customer requirements dictate. This is an extremely exciting development for us and reflects the confidence that North American blower manufacturers place in our products.”

Running alongside PTG Holroyd Precision Rotors’ conventional helical rotor and component manufacturing line, the company’s blower line is equipped to precision mill components of as little as 125 mm in diameter and 300 mm in length, right up to 300 mm in diameter and 1,000 mm in length.

Operating from advanced production facilities in the United States, United Kingdom, and China, PTG Holroyd Precision Rotors is the sister company to PTG Holroyd Precision, the UK-based manufacturer of gear, rotor, screw, and thread milling and grinding machines that produce helical components.

Underlining its expertise and commitment to the efficient manufacture of Roots-type blowers, PTG Holroyd Precision has recently launched a new generation Roots-type blower and helical rotor milling machine. Designated as the 4EX-R-BL (BL = blower), the new machine, supersedes PTG Holroyd Precision’s original 4EXR model and offers manufacturers the flexibility of dual-capability production.

Standard features include a newly designed machine bed and worktable to enable components of up to 500 mm in diameter to be milled, with bed length and width increased to give greater support against the increased cutter forces associated with cutting blower screws. For enhanced milling capability (the original 4EX-R could produce parts of up to 420 mm in diameter), the 4EX-R-BL’s bed height is 150 mm lower than its predecessor, with additional buttress supports providing increased stability during flute milling.

Additionally, the maximum cutter width has been increased from 320 mm to 400 mm to accommodate particularly large rotor profiles.