CEN/TR 17603-32-23:2022

SLOVENSKI STANDARD
01-september-2022
Vesoljska tehnika - Priročnik za pritrdilne elemente
Space engineering - Threaded fasteners handbook
Raumfahrttechnik - Handbuch zu Befestigungsschrauben
Ingénierie spatiale - Manuel de visserie
Ta slovenski standard je istoveten z: CEN/TR 17603-32-23:2022
ICS:
49.030.01 Vezni elementi na splošno Fasteners in general
49.140 Vesoljski sistemi in operacije Space systems and
operations
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL REPORT CEN/TR 17603-32-23

RAPPORT TECHNIQUE
TECHNISCHER BERICHT
June 2022
ICS 49.030.10; 49.140
English version
Space engineering - Threaded fasteners handbook
Ingénierie spatiale - Manuel de visserie Raumfahrttechnik - Handbuch zu
Befestigungsschrauben
This Technical Report was approved by CEN on 13 April 2022. It has been drawn up by the Technical Committee CEN/CLC/JTC 5.

CEN and CENELEC members are the national standards bodies and national electrotechnical committees of Austria, Belgium,
Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia,
Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.

CEN-CENELEC Management Centre:
Rue de la Science 23, B-1040 Brussels
© 2022 CEN/CENELEC All rights of exploitation in any form and by any means
Ref. No. CEN/TR 17603-32-23:2022 E
reserved worldwide for CEN national Members and for
CENELEC Members.
Table of contents
European Foreword . 15
Introduction . 16
1 Scope . 17
2 References . 18
3 Terms, definitions and abbreviated terms . 19
3.1 Terms from other documents . 19
3.2 Terms specific to the present document . 19
3.3 Abbreviated terms. 21
3.4 Variables . 22
3.4.1 Uppercase variables . 22
3.4.2 Lowercase variables . 24
3.4.3 Symbols . 25
3.4.4 Subscripts . 27
4 How to use the guidelines . 28
4.1 Introduction . 28
4.2 Procedure . 28
4.2.1 Stage 1 . 28
4.2.2 Stage II . 29
4.2.3 Stage III . 29
4.2.4 Stage IV . 30
4.3 Annexes . 30
5 General Fastener Analysis Guidelines . 31
5.1 Introduction . 31
5.2 Main Joint Categories . 31
5.2.1 Overview . 31
5.2.2 Concentric Axially Loaded Joints . 32
5.2.3 Eccentric Axially Loaded Joints . 32
5.2.4 Shear Loaded Joints . 32
5.2.5 Combined Loaded Joints. 32
5.2.6 Low Duty Joints . 33
5.3 Joint Analysis Procedure . 37
5.3.1 Overview . 37
5.3.2 Margins of Safety . 37
5.4 Joint Geometry . 39
5.4.1 Fastener Geometry . 39
5.4.2 Thread Geometry . 40
5.5 Safety Factors . 43
5.5.1 Overview . 43
5.5.2 The Joint Fitting Factor . 43
5.6 References . 44
6 The Preload . 45
6.1 Overview . 45
6.2 Coefficient of Utilisation . 45
6.3 Theoretical Aspects . 46
6.3.1 The Relation between Torque and Preload . 46
6.3.2 Determining the Design Torque Level . 49
6.3.3 Locking Devices and Prevailing Torque . 51
6.3.4 Sources of Error . 53
6.3.5 Forces Induced by Thermal Fluctuation . 54
6.4 Mechanisms of Preload Loss . 56
6.4.1 Overview . 56
6.4.2 Embedding . 56
6.4.3 Fastener Group Interaction . 62
6.4.4 Gaskets . 64
6.4.5 Metallic Creep . 64
6.4.6 Washers . 64
6.4.7 Torsional Relaxation . 65
6.5 Margin of Safety on Tightening . 65
6.6 Worked Example . 67
6.7 References . 67
7 Concentric Axially Loaded Joints . 68
7.1 Overview . 68
7.2 Joint Stiffness . 68
7.3 The Joint Diagram . 69
7.3.1 Overview . 69
7.3.2 Compressive Loading . 72
7.4 The Force Ratio . 73
7.5 The Compliance of the Fastener . 73
7.6 The Compliance of the Clamped Parts . 75
7.6.1 Overview . 75
7.6.2 Compression Zone Configurations . 76
7.6.3 Determining the Compression Zone Configuration . 79
7.6.4 The Compression Zone Compliance . 80
7.6.5 Gasket Compliance . 81
7.7 Calculation of the Loading Plane Factor . 83
7.7.1 Introduction . 83
7.7.2 Simple Calculation of the Loading Plane Factor . 87
7.7.3 Analytical Calculation of the Loading Plane Factor . 89
7.8 Joint Separation . 91
7.8.1 Introduction . 91
7.8.2 The Margin of Safety for Joint Separation . 92
7.9 Fastener Tensile Failure . 92
7.9.1 External Vs Overall Load. 92
7.9.2 Margin of Safety on Fastener Failure . 93
7.10 Thread Failure by Shear Pull-Out . 94
7.10.1 Introduction . 94
7.10.2 Failure of the Female Thread . 94
7.10.3 Failure of the Male Thread . 96
7.10.4 Margin of Safety on Thread Pull-Out . 96
7.11 Crushing of Flanges . 97
7.12 Repeated Loading to a Point above Yield . 97
7.13 Dynamic Loading . 99
7.14 Worked Examples. 100
7.14.1 Preload in a Concentric Axially Loaded Joint . 100
7.14.2 Thread Shear Pull-Out Example. 107
7.15 References . 108
8 Eccentric Axially Loaded Joints . 109
8.1 Effects of Eccentricity . 109
8.1.1 Overview . 109
8.1.2 Prying. 112
8.2 Joints with Large Areas of Contact . 112
8.2.1 Compliance of the Clamped Parts . 112
8.2.2 The Joint Diagram . 117
8.2.3 The Force Ratio . 118
8.2.4 Loading Plane Factor . 118
8.2.5 The Interface Opening Limit . 119
8.2.6 Preload Considerations . 119
8.3 Cantilevered Flange Joints .
...