BS A 400:2010 pdf free download AEROSPACE SERIES Specification for nuts, plain and slotted (unified hexagons and unified threads) for shear bolts for aircraft in corrosion‑resisting steel
1 Scope
This British Standard specifies the materials, dimensions, finish and inspection requirements for corrosion-resisting steel nuts with unified hexagons and unified threads for use with shear bolts for aircraft. It makes provision for ranges of plain and slotted nuts.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. BS S 80, High chromium-nickel corrosion resisting steel forging stock, bars, forgings and parts (880 to 1 080 MPa: limiting ruling section 100 mm) BS A 100, Specification for general requirements for bolts and free running nuts of tensile strength not exceeding 1 249 MPa BS EN 2516, Passivation of corrosion resisting steels and decontamination of nickel base alloys
3 General requirements The nuts shall not be used as direct replacements for those conforming to BS A 110 without the authority of the original equipment manufacturer’s Design Authority. NOTE This standard has been created to provide a cadmium free alternative to plain and slotted nuts conforming to BS A 110. The nuts shall conform to BS A 100 in respect of manufacture, screw threads, identification and marking.
4 Material and manufacture
The nuts shall be machined all over from corrosion-resisting steel conforming to BS S 80 (condition: hardened and tempered). 5 Dimensions All finished nuts shall conform to the dimensions and tolerances given in Table 1 or Table 2 as appropriate. NOTE The values in inch units are to be regarded as the standard. A table is given in Annex A to provide a ready means of calculating the approximate millimetre equivalents of the inch dimensions. More accurate conversions should be based on the tables in BS 350. 6 Screw threads The nuts shall have unified threads of the form and class of fit specified in BS A 100.
7 Anti‑corrosion treatment All finished nuts shall be passivated in accordance with BS EN 2516 (material type: ferritic and martensitic chromium steels).
8 Inspection procedure The nuts shall be inspected in accordance with BS A 100.
9 Designation The nuts shall be designated A400-XX 1) , where XX is the part reference suffix specified in Table 1 or Table 2 as appropriate. NOTE For example: A400-ES, A400-ST.