The General Electric Aviation plant in Durham, NC, assembles a number of jet engine types, including those in GE’s GE90 and CF34 product lines, for use in a variety of commercial and military aircraft.

Among the thousands of mechanical fasteners going into each of these engines are about 100 internal spiral retaining rings.

Historically, each retaining ring had to be inserted manually, using a special tool that compressed the retaining ring so it could be positioned at the correct depth inside a cavity. After the ring was placed, an operator would use a second tool to test the ring and make sure it was correctly seated. The entire process was both awkward and labor intensive.

To speed up the process, David Hyde, the lead value process engineer at the plant, contacted O-ring, seal and snap-ring installation machine builder Automated Industrial Systems (Erie, PA). Specifically, he asked for a lightweight, handheld, manually loaded device that would improve both quality and speed.

When using the resulting machine, the operator first loads a retaining ring into the magazine and places the machine’s barrel on the bore where the retaining ring will be installed. The tip of the barrel has a pilot that fits into the bore to ensure accuracy and ease of use.

The operator then pulls a trigger, which activates a small air cylinder that pushes the retaining ring through a tapered barrel where the ring in compressed. When the retaining ring exits the barrel, it snaps into place inside the groove in the bore.

The result has been a system that has increased both throughput and reliability. Total installation times for the 90-plus fasteners going into a single engine have been cut from an hour to less than 10 minutes.

For more on automated and semi-automated O-ring and snap-ring installation, call 814-838-2270 or visit