NEN EN 74-1 : 2005

Foreword
Introduction
1 Scope
2 Normative references
3 Terms, definitions and symbols
   3.1 Terms and definitions
   3.2 Symbols and abbreviations
4 Types and classes of couplers
   4.1 Types of couplers
   4.2 Classes of couplers
5 Reference tubes and bar for coupler tests
6 General requirements
   6.1 Materials
   6.2 Design
   6.3 Manufacturer's drawing
   6.4 Production
7 Test methods and evaluation of results
   7.1 General
   7.2 Slipping and failure force
   7.3 Pull-apart force F[p] (RA)
   7.4 Stiffnesses and ultimate moments
   7.5 Indentation (RA,SW,PA)
8 Designation
9 Marking
10 Test report
11 Evaluation of test results
12 Assessment
13 Product manual
Annex A (normative) Whitworth thread size 1/2 X 12 Tpi
      A.1 Nominal values
      A.2 Tolerances and limiting dimensions after coating
Annex B (informative) Ongoing production control
Bibliography

Defines for right angle couplers, swivel couplers, sleeve couplers and parallel couplers working by friction: - Materials; - Design requirements; - Strength classes with different structural parameters including values for resistance and stiffness; - Test procedures; - Assessment; and gives - Recommendations for ongoing production control. For testing, screw couplers are tightened to a torque of 50 Nm and wedge couplers are tightened with a 500 g hammer until the jarring blow.