AN340 nut — plain hex nut, non-structural, coarse thread

Notes from the standard

• Part number: AN340- (alloy steel), AN340C (corrosion-resistant steel), AN340B (brass) or AN340DD (aluminum alloy), followed by the dash number of the size: AN340-3, AN340C3, AN340B3.
• Cancelled in part after 30 Sep 1970: all dash numbers are cancelled in all materials except dash numbers 3 and 5. The interchangeability table on MS35649 gives the substitute parts.
• No. 10, 1/4, 5/16 and 3/8 sizes: not recommended for new design.
• Aluminum alloy nuts: inactive for design after 19 July 1955.
• Washer face .016 ±.010 thick; an optional chamfer may be used in lieu of the washer face. Chamfer 30° ±5°.
• Thread T per MIL-S-7742, countersunk 110° to the O.D. of the thread.
• Class 2 threads may be substituted for class 2B threads until existing stocks of nuts with class 2 threads are exhausted.
• B is a reference dimension, for design purposes only and not an inspection requirement.
• H is measured at a point approximately halfway between the minor diameter of the hole and the flat of the nut.
• For aluminum alloy nuts, tolerances on A may conform to the applicable material specifications for bar and rod.
• Nuts shall be free of all loose or hanging burrs or slivers which might become dislodged under usage.
• In case of conflict, the requirements of this standard take precedence over those of MIL-S-933.
• Approved data governs. Use the part the SRM, drawing or IPC calls for.