Expansion Nuts are vibration-resistant fasteners that provide quick attachment in blind or center-panel locations. These Expansion Nuts have spring legs for self-retaining in rectangular holes. If permanent retention is required, a special locking tab can be provided. Design variations accommodate box or robotics styles. Easy to apply, Expansion Nuts can be used in place of weld-, clinch-, or stake-type fasteners. No masking is required because they will not clog when painted either before or after installation.