Pignose washer

• A company called Kirkhill Rubber Products in Los Angeles, California, made the pignose washer. As of 1944, Kirkhill had sold millions of pignose washers. Kirkhill promised that its pignose washers outlasted other washers by as much as five years.
  
  

Construction

• According to Kirkhill advertising from the 1940s, Pignose washers were made of 13 scientifically blended ingredients. Kirkhill marked every washer made with the name "pignose."
  
  

Difference

• Most washers are flat, without an upside or a downside. Pignose washers, however, were thick, with beveled edges that flared out in the middle and sloped back in toward the middle of the washer before they flattened out at either end.