BS EN 2943:2024
Aerospace series. Insert, MJ and M screw threads, helical coil. Technical specification

Standard No.

BS EN 2943:2024

Release Date

2024

Published By

British Standards Institution (BSI)  GB  /  BSI

Latest

BS EN 2943:2024

Introduction

Background of standard update and technological evolution

BS EN 2943:2024 replaces the 2019 version of the standard. The main technical changes include:

• Update the list of normative references
• Revise the manufacturer certification requirements (Clause 4.1-4.2)
• Expand the torque value table for MJ thread and M thread (Table 4-5)
• Add thread type test specification (Appendix A)

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Comparison of core technical requirements

Technical parameters	2019 version	2024 version	Range of changes
Thread type coverage	12 types	21 types	+75%
Maximum test torque (MJ10×1.5)	19 Nm	19 Nm	Unchanged
Repeated use test cycle	10 times	15 times	+50%

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Key quality control points

Material specifications

Thread insert materials must meet:

• Heat-resistant steel: FE-PA2601 in accordance with EN 2398
• Nickel-based alloy: NI-P100HT in accordance with EN 3219
• Bronze materials need to pass PTFE lubrication test

Torque performance test

Three types of key torque indicators:

1. Self-locking torque: The critical value to prevent the bolt from loosening
2. Disengagement torque: The torque required to start the bolt rotation
3. Seating torque: The torque to establish axial preload

Example: The disengagement torque range of MJ8×1.25 thread is 0.65-12.0 Nm

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Implementation recommendations

Purchasing considerations

• Confirm that the supplier has EN 9100 Aviation Quality Management System Certification
• A complete material traceability report is required
• The sampling plan is implemented according to Table 2, and the destructive test sample size is ≥5 pieces

Field Application Guide

• Control the speed during installation to avoid the temperature exceeding 45℃
• Use the assembly procedure specified in EN 2945
• Bronze inserts must use PTFE-containing lubricant

BS EN 2943:2024 Referenced Document

• EN 2398 Aerospace series - Heat resisting steel FE-PA2601 (X6NiCrTiMoV26-15) - Rm greater than or equal to 900 MPa - Bars for machined bolts - D less than or equal to 25 mm
• EN 2945 Aerospace series - Inserts, screw thread, helical coil, self-locking - Assembly procedure
• EN 3044 Aerospace series - Installation holes for inserts, screw thread, helical coil, self-locking - Design standard
• ISO 21920-3 Geometrical product specifications (GPS) — Surface texture: Profile — Part 3: Specification operators
• ISO 5855-1 Aerospace - MJ threads - Part 1: General requirements
• ISO 5855-2 Aerospace - MJ threads - Part 2: Limit dimensions for bolts and nuts
• ISO 965-2 ISO general purpose metric screw threads - Tolerances - Part 2: Limits of sizes for internal and external threads (tolerance classes 6H and 6g for M1,6 to M100 and 5H and 6h for M1 to M1,4)*， 2024-11-15 Update

BS EN 2943:2024 history

• 2024 BS EN 2943:2024 Aerospace series. Insert, MJ and M screw threads, helical coil. Technical specification
• 0000 BS EN 2943:2019(2020)
• 2020 BS EN 2943:2019 Aerospace series. Inserts, MJ and M screw threads, helical coil. Technical specification
• 1998 BS EN 2943:1998 Inserts, screw thread, helical coil, self-locking - Technical specification

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