ORLANDO, Fla.—Precision Associates Inc. has developed a tiny O-ring, so small it fits snugly into the ear of President Franklin D. Roosevelt on the U.S. dime.
The 4-4 O-ring's inner diameter and the cross-section diameter measure at 0.004 inches.
“We make a lot of very tiny seals and precision seals. We specialize in close tolerance,” said Marty Loso, PAI's vice president of sales and marketing. “We wanted to see how small of a part we could make.”
The ring was introduced to the market in October 2013 and promoted at the 2014 Gasketing and Converting Expo in Orlando. Loso said the firm has been making progressively smaller O-rings and custom parts over the years.
The 4-4 O-ring has only been used in research and development programs thus far, Loso said. The firm would not disclose its specific use yet, but the majority of the O-rings it sells in the 0.03 inch and under range are used in electronics applications, many in the medical sector.
Loso said customers have responded favorably and that has generated additional interest in other micro-molded rubber items.
PAI develops the ring at its facility in Minneapolis, Minn. Loso said the firm has been in business since 1955 and primarily manufactures rubber seals. He said PAI has more than 1,000 compounds and 20 polymers with custom jobs accounting for 30 percent of its business.