BS ISO 7961:2021 pdf download – Aerospace — Bolts — Test methods
This document specifies test methods for bolts for aerospace constructions.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements 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.
ISO 7500-1, Metallic materials — Calibration and verification of static uniaxial testing machines — Part 1:
Tension/compression testing machines — Calibration and verification of the force-measuring system
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Tests
4.1 Tensile test at ambient temperature
4.1.1 Apparatus Test device (see Figure 1). The test device shall be centred such that the stress at four equi-spaced points around the test sample is uniform within 1 %, or such that the coaxiality between the bolt and the clearance holes is
less than or equal to 0,025 mm to ensure the application of the tensile load along the axis of the bolt.
Calibration requirements of the test device shall conform to ISO 7500-1 and Annex A.
Other types of device may be used provided they respect the requirements of Figure 3. Cups, fixed or removable, in conformity with Figure 3, which specifies only functional requirements. Test nut (free-running or self-locking) or threaded part (assuming the role of a nut), of sufficient strength to guarantee bolt failure. Tapered spacer, placed under the head during the test, when required by the procurement specification or definition document to evaluate the effect of angularity. The minimum clearance between the hole and the bolt shank shall be 0,13 mm. At least 90 % of the bolt bearing area shall be supported by the spacer which shall have a diameter sufficient to support the width across the corners of the bolt. The tolerance on the hole diameter in the spacer shall be 0 0 08 + , mm. Washers, used under bolt heads or nuts only in the case outlined in Tensile or compressive test machine, depending on the fixture, capable of applying the test loads. 4.1.2 Procedure Assemble the bolt in the test device ( as shown in Figure 1. Install the nut ( as shown in Figure 2. Place the complete assembly between the loading platens of the machine. Apply the load until the bolt breaks at the rate specified in Table 1, in a controlled way.BS ISO 7961 pdf download.