D4 DZUS Standard Line Quarter-Turn Fasteners. Stud selection Size 4. Stud Length Table A B K U L TMT Range For: Rivet-On Receptacle D4-S4-225 TMT Range For: Rivet-On Receptacle D4-S4-200 TMT Range For: Weld-On Receptacle D4-X485-300 TMT Range For: Weld-On Receptacle D4-X485-275. Min. How To Measure for Selecting Dzus Fasteners . Dzus Fastener , Quick Turn Fastener Measurement Guidelines. To Find (A) Fastener Length, Add Together (B) Spring Reach and (C) Material Thickness (Including Bracket If Applicable). Selecting Quarter-Turn Fastener s. The stepped-spring can be flipped over and used with thinner material, when a shorter-reach fastener is used. Take your measurement by adding the thickness of the material to the installed spring height. The installed height of a flat spring is approximately .150-.175 inches, and a stepped spring is .400-.425 inches.

Measuring Dzus Springs. Dzus Springs are available in 1″ and 1-3/8″ sizes. The size is determined by the distance between the rivet centres of the spring. The height or reach of the spring is measured as per the diagram to the left. This is the size of Dzus fastener you need. The sizes below are the total of both panels, the one with the clip attached and the panel you are fastening to it. Please account also for any gaps between the two panels. We supply 2 washers that are 0.5mm thick each, so this accounts for 1mm. Dzus fasteners are a type of proprietary quarter-turn lock fastener that are often used to secure skin panels on aircraft and other high-performance vehicles.