S-99904A102 5/16"-18 Flange Nuts

Key Features & Benefits at a Glance

• Superior vibration resistance with anti-loosening serrations that maintain clamp force in high-stress environments
• Enhanced corrosion protection through zinc-plated steel construction for extended service life in harsh conditions
• High-strength performance with Grade 5 classification ensuring reliable performance in demanding applications
• Integrated flange design eliminates need for separate washers while providing superior load distribution
• Quick installation with UNC coarse threads that engage faster and resist cross-threading
• Precise thread engagement with Class 2B fit ensuring consistent performance and easy assembly
• Standard external hex drive allows for conventional tooling and familiar installation procedures

Professional Applications & Engineering Value

This Grade 5 zinc-plated steel flange lock nut delivers critical vibration resistance where traditional fasteners fail. The integrated flange design with 11/16" diameter provides exceptional bearing surface, distributing clamp load effectively while eliminating separate washers. The anti-loosening serrations bite into mating surfaces, creating permanent resistance to rotational forces in heavy machinery, automotive assemblies, and structural frameworks. Manufactured with UNC coarse threads (5/16"-18), this fastener ensures rapid installation in production environments while the zinc-plated steel construction offers reliable corrosion protection for outdoor equipment and industrial applications exposed to moisture and chemicals. The external hex drive profile maintains compatibility with standard wrench sets, streamlining maintenance procedures.

Specification Summary & Compliance

This flange lock nut features 5/16"-18 UNC coarse threads with Class 2B thread fit for precise engagement and consistent performance. The fastener meets Grade 5 strength classification and incorporates a standard hex profile with 1/2" width and 9/32" height. Manufacturing complies with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental standards, ensuring safe usage across industrial sectors. The right-hand thread direction and external hex drive style provide familiar installation characteristics for maintenance professionals.