Processes & Solutions

"Cold Forming" is the umbrella term which includes all the specific services that Glyne provides - rotary swaging, tube butting, and end forming. Cold-forming simply means that all work is done at room temperature. Although the majority of our work is single process, in many cases our products will integrate two or even all three of these processes.

We also provide secondary operations, both in-house and through qualified shops with which we've done business for decades. We work with all alloys of aluminum, most grades of corrosion resistant steel, aircraft and non-aircraft steel, copper, brass and silver.

• SWAGING

• TUBE BUTTING

• END FORMING

• SECONDARY OPERATIONS

Rotary swaging is a process for reducing the diameter of a length of tubing. The reduced diameter can be any length, from a short end up to the entire length of the tube, or any length in between. The tubing is fed by hand, or mechanically, into custom made, hardened steel dies. Through the reciprocating action of the die halves, the tube is worked into the shape cut in the dies. Glyne has 16 swagers capable of handling up to 2.75" diameter, and tapers up to 15" long in a single pass.

The Benefits of Rotary Swaging:

• Cost-effective process
• Increased tensile strength
• An improved surface finish


Tube is fed into swager		Replacing the retaining ring on the front of the swager

Swaged tube set in the die that produced it
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Butting creates a tube with a varying wall thickness while maintaining a constant outside diameter. Typically, you would have a heavier wall on both ends where the tube is to be joined to other parts, and a thinner wall in the middle in order to conserve weight. The bicycle industry is a large consumer of this type of formed tubing. Our 2 butting machines can form tubing up to 4" in diameter and 42" long.

Tubes ready for butting

Cross-sectioned, butted tube showing change in wall thickness

Tube end forming includes expanding, flaring, beading and flanging. Tubing is clamped in a set of holding dies while a forming die is advanced into the end of the tube. We have 4 different end formers which can handle tubing from 1/16" diameter up to 4.0" in diameter.

Preparing tube for end forming

A tube after end-forming

Beaded tubes


In-house secondary operations include honing, single hole punching, drilling, limited machining and non-aircraft aluminum heat treating. We have also invested $60,000 in an aqueous power washer so that tubes leave the shop clean. Aircraft carbon steel parts are individually bagged and coated with rust preventive. Outside services we contract on a frequent basis include bending, centerless grinding to +/- .0002", precision machining (including threads to MIL-S-8879), non-destructive testing, heat treating, and all finishes.

Production honing machine		Loading tubes into the power washer

Drilling and counterboring the end of a swaged tube