BS EN 2939:2024
Aerospace series. Screw, 100° countersunk head, offset cruciform recess, threaded to head, in heat resisting steel FE-PA92HT (A286). Classification: 900 MPa (at ambient temperature)/650 °C
- Standard No.
- BS EN 2939:2024
- Release Date
- 2024
- Published By
- British Standards Institution (BSI) GB / BSI
- Latest
- BS EN 2939:2024
- Introduction
Analysis of core changes in the standard
Technical elements 1994 edition 2024 edition Impact of changes Drive slot coding Not specified New ISO 14275/14276 classification Achieving international compatibility Material specifications Citing old EN standards Updated to EN 2398/2399 Material performance traceable Definition of terms Missing New Chapter 3 Remove ambiguity
Key technical characteristics
Material performance requirements
The standard stipulates the use of FE-PA92HT(A286) heat-resistant steel, and its key indicators are:
- Room temperature tensile strength ≥900MPa
- Maximum operating temperature 650°C
- Material must comply with EN 2398 (for machining) or EN 2399 (for forging)
Structural features
Typically used in aircraft engine hood fixation, its special design includes:
- 100° countersunk head angle ensures flush installation
- Offset cross groove (ISO 14275) provides higher torque transmission
- Fully threaded design enhances vibration resistance
Application Guide
Selection Comparison Table
Thread Code Diameter (mm) Applicable Length (mm) Reference Weight of Single Component (g) MJ3×0.5 2.68 6-42 0.43-2.02 MJ5×0.8 4.48 10-70 1.75-9.50 Key points for quality control
- The marking method shall be in accordance with EN 2424, and type F marking shall be used for diameter ≤4mm
- The thread shall comply with the 4h6h tolerance grade of ISO 5855-2
- There shall be no depression on the head (see item g in Figure 1)
BS EN 2939:2024 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 2399 Aerospace series - Heat resisting steel FE-PA2601 (X4NiCrTiMoV26-15) - Rm Greater than or equal to 900 MPa - Bars for forged bolts - D less than or equal to 25 mm
- EN 2424 Aerospace series - Marking of aerospace products
- EN 3043 Aerospace series - Fasteners, externally threaded, in heat resisting steel FE-PA92HT (A286) - Classification: 900 MPa/650 °C, manufacturing method optional - Technical specification*， 2025-12-24 Update
- ISO 14275 Aerospace - Drives, internal, offset cruciform, ribbed - Metric series
- ISO 14276 Aerospace - Drives, internal, offset cruciform - Metric series
- ISO 3353-1 Aerospace - Lead and runout threads - Part 1: Rolled external threads
- ISO 5855-2 Aerospace - MJ threads - Part 2: Limit dimensions for bolts and nuts
BS EN 2939:2024 history
- 2024 BS EN 2939:2024 Aerospace series. Screw, 100° countersunk head, offset cruciform recess, threaded to head, in heat resisting steel FE-PA92HT (A286). Classification: 900 MPa (at ambient temperature)/650 °C
- 1994 BS EN 2939:1994 Screws, 100° countersunk head, offset cruciform recess, threaded to head in heat resisting steel FE-PA92HT (A286). Classification: 900 MPa (at ambient temperature)/650°C
Standard and Specification
SS-EN 2939:2024 Aerospace series — Screw, 100° countersunk head, offset cruciform recess, threaded to head, in heat resisting steel FE-PA92HT (A286) — Classification: 900 MPa (at ambient temperature)/650 °C
UNI EN 2939:2024 Aerospace series - Screw, 100° countersunk head, offset cruciform recess, threaded to head, in heat resisting steel FE-PA92HT (A286) - Classification: 900 MPa (at ambient temperature)/650 °C
EN 2939:1994 Aerospace series - Screws, 100° countersunk head, offset cruciform recess, threaded to head, in heat resisting steel FE-PA92HT (A286) - Classification: 900 MPa (at ambient temperature)/650 °C
ASD-STAN PREN 2939:2023 Aerospace series — Screw, 100° countersunk head, offset cruciform recess, threaded to head, in heat resisting steel FE-PA92HT (A286) — Classification: 900 MPa (at ambient temperature)/650 °C
DS/EN 2939:1995 Aerospace series - Screws, 100° countersunk head, offset cruciform recess, threaded to head, in heat resisting steel FE-PA92HT (A286) - Classification: 900 MPa (at ambient temperature)/650 °C
DS/EN 2940:1996 Aerospace series - Screws, 100° countersunk head, offset cruciform recess, threaded to head, in heat resisting steel FE-PA92HT (A286), silver plated - Classification: 900 MPa (at ambient temperature)/650 °C
UNE-EN 2939:2024 Aerospace series - Screw, 100° countersunk head, offset cruciform recess, threaded to head, in heat resisting steel FE-PA92HT (A286) - Classification: 900 MPa (at ambient temperature)/650 °C
EN 2939:2024 Aerospace series - Screw, 100° countersunk head, offset cruciform recess, threaded to head, in heat resisting steel FE-PA92HT (A286) - Classification: 900 MPa (at ambient temperature)/650 °C
NS-EN 2939:1994 Aerospace series - Screws, 100° countersunk head, offset cruciform recess, threaded to head, in heat resisting steel FE-PA92HT (A286) - Classification: 900 MPa (at ambient temperature) / 650 °C