The MS51959-31 is a military-standard machine screw with a flat countersunk head, used in aerospace and aircraft assemblies where a flush, smooth surface finish is required. The 82° countersunk head allows the screw to sit level with the material surface, making it suitable for aerodynamic panels and interior finishing applications.

This fastener is commonly used in aircraft interior structures, access panels, fairings, and light-duty airframe components where space is limited and vibration resistance is important. It provides secure fastening while maintaining a clean external profile.

Manufactured to MS specifications, the screw is typically made from corrosion-resistant stainless steel (18-8 / 300-series) with a passivated finish for durability in aviation environments exposed to moisture, vibration, and temperature changes.

Key features include:

MS51959-31 aerospace machine screw
82° flat countersunk head (flush installation)
#6-32 UNF thread
Stainless steel (18-8 / 300-series) construction
Passivated corrosion-resistant finish
Phillips drive for standard installation tools
Used in aircraft interiors, panels, and fairings
Suitable for vibration and cyclic load environments
Lightweight aerospace fastener
Direct replacement per MS aircraft hardware standards