AN960D3016L

Source notes and limits

• Material code (AN960 sheet 1, Req. 1): Aluminum alloy 2024 (Alclad) per QQ-A-250/5, condition T3 or T4 (D code). Coating (Req. 2): no code, untreated (Table I column "UNTREATED").
• Suffix "L" is a thickness code read from Table I; it is not the same thickness in every row or material (sheet 2 note 4, struck: "REGULAR SERIES - NO CODE; LIGHT SERIES - L CODE; EXTRA LIGHT SERIES - LL CODE (DESIGNATES .016 THICKNESS WHERE L DESIGNATES .032 THICKNESS); MEDIUM SERIES - M CODE (DESIGNATES .032 THICKNESS WHERE L DESIGNATES .016 THICKNESS)").
• "INACTIVE FOR NEW DESIGN. NAS 1149 MAY BE SUBSTITUTED IN ALL APPLICATIONS." (AN960 sheet 1).
• AN960 REVISION 21, dated 6 AUGUST 1992, is hereby cancelled. Future acquisitions for this product should refer to NAS1149, “Washer, Flat”. (Notice 1, 16 September 2011, p.1). Substitute printed for AN960D3016L: NAS1149D3016H (Notice 1 Interchangeability and Substitution Table). NAS1149 part numbers are not decoded here.
• CAUTION: The supersession information is valid as of the date of this notice and may be superseded by subsequent revisions of the superseding document.
• Thickness tolerance (sheet 2 note 2): DIMENSIONS IN INCHES - TOLERANCES ON THICKNESS: FOR ALUMINUM ALLOY WASHER: .016 ± .003; .032 ± .004; .042 ± .004; .049 ± .005; .063 ± .006; .090 ± .007. ALL OTHER MATERIALS: ± .010.
• FAA AC 43.13-1B para 7-86 (p.7-15): "PLAIN WASHERS (AN960 AND AN970). Plain washers are widely used with hex nuts to provide a smooth bearing surface, act as a shim to obtain the proper grip length, and to position castellated nuts in relation to drilled cotter pin holes in bolts. Use plain washers under lock washers to prevent damage to bearing surfaces. Cadmium-plated steel washers are recommended for use under boltheads and nuts used on aluminum alloy or magnesium structures to prevent corrosion. The AN970 steel washer provides a larger bearing surface than the plain type, and is often used in wooden structures under boltheads and nuts to prevent local crushing of the surface."
• FAA AC 43.13-1B para 7-37 (p.7-5): "Bolts of slightly greater grip length may be used, provided washers are placed under the nut or bolthead. The maximum combined height of washers that should be used is 1/8 inch. This limits the use of washers necessary to compensate for grip, up to the next standard grip size."