ISO 9140 pdf download.Aerospace — Nuts, plain or slotted (castellated) — Test methods
1 Scope
This International Standard specifies test methods for metric plain or slotted (castellated) nuts, with MJ threads in accordance with ISO 5855-2, for use in aerospace construction. It describes the test device and the method for each test. It is applicable to nuts as defined above, provided that the relevant documents (product standard, definition document, procurement specification, etc.) refer to this International Standard. This International Standard is to be used in conjunction with ISO 91 39 or any other similar document.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 691 :1 997, Assembly tools for screws and nuts — Wrench and socket openings —Tolerances for general use . ISO 1 024:1 989, Metallic materials — Hardness test — Rockwell superficial test (scales 1 5N, 30N, 45N, 1 5T, 30T and 45T) . ISO 5855-2:1 988, Aerospace — MJ threads — Limit dimensions for bolts and nuts . ISO 6507-1 :1 997, Metallic materials — Vickers test hardness — Part 1 : Test method . ISO 6508:1 986, Metallic materials — Hardness test — Rockwell test (scales A – B – C – D – E – F – G – H – K) . ISO 91 39:1 998, Aerospace —Nuts, plain or slotted (castellated) — Procurement specification.
3 Inspections and tests
3.1 Hardness test 3.1.1 Procedure The procedure is a function of the nut configuration and of the available apparatus. The authorized procedures are as follows: – Rockwell hardness, in accordance with ISO 6508; – Vickers hardness HV 5 to HV 1 00, in accordance with ISO 6507-1 ; – Rockwell superficial hardness, in accordance with ISO 1 024; – microhardness. 3.1.2 Method This test shall be carried out at ambient temperature. The measurement shall be taken on the bearing surface or on one of the flats. Should this not be possible, carry out this test on a cut section after moulding the nut into a thermosetting resin. Remove all possible coating (protection, lubrication, paint, etc.) in the measurement zone. True up the bearing surface to obtain the required relationship. These two operations shall not generate any heat liable to modify the characteristics of the material constituting the nut to be tested. Carry out the test and then check conformity with the requirements of the dimensional standard or of the definition document. Nuts subjected to this test shall not be reused. 3.2 Bearing surface squareness test 3.2.1 Test device The test device is illustrated in Figure 1 . The test device includes the following elements: a) a threaded mandrel with an end in accordance with ISO 5855-2, except for the pitch diameter which shall be in accordance with the values specified in Table 1 ; b) a collar sliding on the plain portion of the threaded mandrel the external diameter B of which shall be at least equal to the across flat dimension of the nut to be tested; c) a feeler gauge the thickness of which shall be equal to the permissible out-of-squareness specified in the product standard, in the definition document or the procurement specification.
3.2.2 Method The test shall be carried out at ambient temperature. Manually screw the nut to be tested onto the mandrel until the thread is fully engaged. Move the collar into contact with the nut. Evaluate the out-of-squareness by means of the feeler gauge then check conformity with the requirements of the product standard, or the definition document or the procurement specification. 3.3 Axial load test 3.3.1 Test device The test device is illustrated in Figure 2.