A circular-shaped item designed to maintain predetermined distance between assembled parts and/or for distributing pressure or preventing endwise movement between member parts. It has a solid cross-section and two flat parallel bearing surfaces. The distance between the bearing surfaces perpendicular to the axis of the centrally located hole shall not exceed 25 percent of the outside diameter. The diameter of the centrally located hole must exceed 75 percent of the outside diameter. Excludes laminated items. For items manufactured from impregnated graphite or lubricated nonmetallic materials, excluding felt or plastics, see gasket. For items manufactured from lubricated plastics, see bearing, washer, thrust. For items manufactured from lubricated felt, see felt, mechanical, preformed. Excludes disk, valve; insulator washer; and shim. See also spacer, plate and spacer, sleeve.
Indicates there is no data in the hmirs and the nsn is in a fsc not generally suspected of containing hazardous materials.
Precious metal content is unknown
The item does not have a nuclear hardened feature or any other critical feature such as tolerance, fit restriction or application.
HMIC: Hazardous Material Indicator Code. A one position code that identifies a hazardous item.
PMIC: Precious Metal Indicator Code. A one position code which identifies items that have precious metals as part of their content. precious metals are those metals generally considered to be uncommon, highly valuable, and relatively superior in certain properties such as resistance to corrosion and electrical conductivity.
ESD: Electrostatic Discharge. Indicates if an item is susceptible to electrostatic discharge or electromagnetic interference damage. electrostatic discharge damage occurs when an accumulation of static electricity generated by the relative motion or separation of materials is released to another item by direct contact. electromagnetic interference damage occurs when an item comes into proximity with an electrostatic or magnetic field.
ENAC: Enviromental Attribute Code. Identifies items with environmentally preferred characteristics.
CRITL: Criticality Indicator Code. Indicates an item is technically critical by tolerance, fit, application, nuclear hardness properties, or other characteristics.