EN 14831:2005

Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols and units
5 Test principle
6 Apparatus
  6.1 Test device
  6.2 Test fixture
  6.3 Reference fasteners
  6.4 Fasteners to be tested
7 Test procedure
  7.1 General
  7.2 Test procedure for nut testing
  7.3 Test procedure for bolt/screw testing
8 Evaluation of the results
9 Test report
Annex A (normative) Calibration method for determination
        of the angle theta[test]
Annex B (normative) Determination of the control limit
        values for the torque (T[min] and T[max])
Annex C (informative) Example of determination of the control
        limit values for the torque (T[min] and T[max])
Bibliography

This European standard specifies a test method for fasteners with ISO metric thread from M6 to M16 and with property classes 8.8 to 12.9 for bolts and screws and with property classes 8 to 12 for nuts, to check their tightening performance in the elastic range.It applies to steel fasteners with an ISO metric thread according to ISO 68-1.It applies to fasteners having a friction coefficient from 0,06 up to and including 0,18. For higher values of friction coefficients, the dispersion of test results increases and the test method should not be applied. For lower values friction of coefficients, which are for very specific applications and require special lubrication, this standard does not apply.This comparative test method can be used to monitor stability of a production process (such as coating, lubrication, shot-blasting) or to compare various production manufacturing lots. It can also be used to detect fasteners, which are out of specification.NOTEThis simplified test method has been developed to avoid systematic use of more complex procedures.In case of dispute the torque/tension test method according to EN ISO 16047 is the referee test.This standard does not apply for assessment of fasteners in actual assembly conditions; it does not allow the measurement of operating friction coefficients.