Measuring Quarter Turn Fasteners

Measuring Quarter Turn Fastener Length or Grip

The correct way to measure the length or grip of a Quarter Turn Fasteners or Dzus Fasteners is to measure from under the head of the fastener to the bottom of the spring locking area. Flush Head and Self-Ejecting Quarter Turn Fasteners are measured from the top of the head to the bottom of the spring locking area.

Measuring the Diameter of Quarter Turn Fasteners 

Bullant Performance Products stock Quarter Turn Fasteners with various diameters. The diameter of a Quarter Turn Fastener is determined by the shaft of the fastener. If the the Quarter Turn Fastener is an undercut style the widest section of the shaft is used to determine the diameter. To confuse things a little the diameter of 7/16″ Dzus Fasteners measures .406″, not 7/16″ (.437″). As the fasteners are manufactured in the USA the diameter is displayed in fractions of inches. The most common diameter Quarter Turn Fasteners we sell is 5/16″ and 7/16″.

Measuring Quarter Turn Fastener Springs

Quarter Turn Fastener Springs are available in 3/4″, 1″ and 1-3/8″ sizes. The size is determined by the distance between the rivet centres of the spring. As a rule 3/4″ Springs are used with 1/4″ diameter Quarter Turn Fasteners, 1″ Springs with 5/16″ Quarter Turn Fasteners and 1-3/8″ Springs with 7/16″ Quarter Turn Fasteners.

Quarter Turn Springs are available in different heights to assist with achieving the correct fit. The height or reach of the spring is measured as per the diagram.