Designers often struggle to find the perfect ring or spring to meet their application. Traditionally, engineers design around existing standard components like springs and retaining rings when developing new products.
Frequently, a custom solution could offer major performance and cost advantages, but the need for expensive tooling has been cost prohibitive.
One manufacturer, Smalley Steel Ring, has developed a “No-Tooling-Cost” process to inexpensively and quickly produce specialized parts for specialized applications.
No-Tooling-Cost Process Meets Edgewound Part Production
The No-Tooling-Cost process involves precision forming operations that coil pre-tempered flat wire on an edge to create a near-perfect circle.
Spirolox External 3 Turn Retaining Ring Yellow. (Image courtesy Smalley Steel Ring Company.)
The forming process works in the direction if the grains already present in the material. This gives products greater strength and stability than conventional rings and springs, which are simply stamped through the base metal grain.
Smalley’s unique coiling process begins with round wire that is flattened to produce a close tolerance feedstock. This allows finished parts to hold tighter tolerances than stamped rings or springs. Once the flat feedstock material has been developed, a great range of manufacturing flexibility is available.
“There would be a speed advantage because no special tool has to be made for a special product,” says Ben Moskalik, senior research and development engineer with Smalley. “There’s cost savings in that fact.”
A complex custom wave spring. (Image courtesy Smalley Steel Ring Company.)
Some of Smalley’s more unusual products come from the energy industries.
“With oil and gas industries, their components tend to be quite large. I’m talking about six to eight inches in diameter and even bigger,” explained Moskalik. However, Smalley’s largest No-Tooling-Cost projects are usually for green technologies. “The biggest diameter we’ve gone up to would be 120 inches. Those could be used in wind turbines.”
On the flip side, the medical industry has required some of Smalley’s tiniest productions.
“The smallest part we’ve produced so far is around 0.178 inches in diameter. We’re always pushing those limits.” Moskalik continues, “I’d love to go down to 0.150 and even smaller as the future goes on. My role in research and development is to push our machines’ limits all the time.”
Eliminating Waste Material with Coiled, Ambidextrous Rings and Springs
Rings stamped out of sheet metal leave significant amounts of “skeleton” scrap. This scrap metal has little value and is ultimately no more than wasted money.
Coiled retaining rings and wave springs are edgewound to exact tolerances, producing minimal scrap or material waste. This also allows for the economical production of specialty alloys such as 316 stainless steel, Inconel, Elgiloy, phosphor bronze, titanium and more.
“There’s no waste of materials [in the No-Tooling-Cost process],” said Moskalik. “With anything over an inch and a half in diameter or larger, you tend to start seeing a much more substantial savings in material costs because you’re wiping out all of that skeleton scrap. With exotic alloys, the material costs are so much more that any diameter can start giving you savings right away.”
The No-Tooling-Cost process is set up to provide quick access to prototype parts.
Manufacturers can determine any necessary changes to diameter, material size, alloy or any other characteristic to ensure the final products are exactly what they need for their assembly. A late redesign involving an increase in spring rate, for example, might be accommodated by a material change or a switch to thicker material, more waves or a different design entirely.
Moskalik says even ambidextrous parts are possible to produce quickly.
“Our parts are ambidextrous, made with cold rolled wire and are uniform all the way around. When we coil it there’s no drag points or anything that would create a burr during our process as seen in stamped products and so there really is no left, right, up, down, front or back – it’s going to be the same either way.”
This flexibility helps keep design timelines on track and reduces the number of configuration changes in the design process.
Design Help for Custom Rings and Springs
Smalley is able to produce custom rings or springs using readily available materials, like high carbon steel, to more exotic materials like Inconel to meet delivery requirements.
The best thing customers can do to speed up the ordering process is to plan ahead. “The easiest way to go about ordering is to visit our website and we have checklists for springs and rings that asks the questions that we would be asking on the phone,” Moskalik said.
Questions focus on what diameters, performance settings and materials a customer may need. Even the parts’ working environment is called into question.
“Customers can always call us or submit information on the website for whatever special design they need or question they may have,” Moskalik added.
For customers who use just-in-time inventory control, Smalley offers stock parts for immediate shipment. Custom or stock part springs and retaining rings are often specified, but not engineered at the design phase.
The ability to spec custom designs quickly at low cost can mean the difference between an on-time, on-budget product or a costly redesign.
For more information on Smalley Steel Ring’s No-Tooling-Cost process, visit smalley.com.
Smalley Steel Ring has sponsored this post. They have no editorial input into this post. All opinions are mine. James Anderton.