The MS35335-33 is a military-standard external tooth lock washer used in aerospace and industrial assemblies to prevent loosening of fasteners under vibration and dynamic loads. The toothed outer edge bites into both the fastener head and the mating surface, creating a strong mechanical lock.

It is typically used with 1/4" screws or bolts and is common in aircraft structures, engine accessories, and general airframe hardware where vibration resistance is critical. These washers are designed for single-use or limited reuse, as the teeth deform during tightening.

Manufactured to MS specifications, it is made from spring steel (often cadmium plated or corrosion-protected depending on variant), providing high hardness and reliable locking performance in demanding environments.

Key features include:

MS35335-33 aerospace external tooth lock washer
Designed for 1/4" fasteners
Prevents loosening under vibration
External teeth bite into mating surfaces
Spring steel construction
Cadmium or corrosion-protected finish (spec dependent)
Used in aircraft and high-vibration assemblies
Typically sold in 100 pcs packs
Single-use locking action due to tooth deformation
Direct replacement per MS aircraft hardware standards