BS 7774:1994
Current
The latest, up-to-date edition.
Threaded fasteners. Axial load fatigue testing. Test methods and evaluation of results
Hardcopy , PDF
English
15-08-1994
Important note : Users cannot be edited or removed once added to your Multi user PDF.
Committees responsible
National foreword
Specification
1 Scope
2 Normative references
3 Symbols and their designations
4 Principle
5 Apparatus
6 Test procedure
7 Evaluation of results
8 Test report
Tables
1 Symbols and their designations
2 Order system for the statistical evaluation of 8
fatigue tests with a stress amplitude of sigma a =
150 N/mm2 in the finite life range
3 Example of the evaluation of fatigue tests by the
staircase method
Figures
1 Fixture without insert
2 Fixture with insert
3 Load verification stud
4 Stress distribution in the shank of the load
verification stud
5 Threaded test adapter
6 Test washer (assembled)
7 Location of test nut
8 Probability of failure pf and number of stress
cycles in the finite life range, determined on the
basis of 8 fatigue tests with sigma a = 150 N/mm2
9 Example of the execution and evaluation of fatigue
tests according to the boundary method
10 Wohler curve (S/N curve) sigma a = f(N)
11 Example of basic pattern of combined test method
with 14 specimens
12 Example of Wohler curve (S/N curve)
13 Haigh diagram
Specifies the conditions for carrying out axial load fatigue tests on threaded fasteners, as well as recommendations for the evaluation of the results. Includes tables, diagrams, and symbols and their designations.
| Committee |
FME/9
|
| DevelopmentNote |
Also numbered as ISO 3800 Supersedes 91/83077 DC (10/2005)
|
| DocumentType |
Standard
|
| Pages |
24
|
| PublisherName |
British Standards Institution
|
| Status |
Current
|
| Supersedes |
This International Standard specifies the conditions for carrying out axial load fatigue tests on threaded fasteners, as well as recommendations for the evaluation of the results.
Unless otherwise agreed, the tests are of the fluctuating tension type and are carried out at room temperature, the loading applied being centric along the longitudinal axis of the fastener. The influence of the compliance of clamped parts on the strain of the fastener is not taken into account.
This method allows determination of the fatigue strength of threaded fasteners.
The test results can be influenced by the test conditions. For this reason, minimum requirements are specified to reduce this effect. In addition, calibration and centring control methods for the testing apparatus are included.
| Standards | Relationship |
| SNV ISO 3800 : 1993 | Identical |
| BS EN 24033:1992 | Hexagon nuts, style 2. Product grades A and B |
| BS 4395-1:1969 | Specification for high strength friction grip bolts and associated nuts and washers for structural engineering General grade |
| BS 4190:1967 | Specification for ISO metric black hexagon bolts, screws and nuts |
| BS 4183:1967 | Specification for machine screws and machine screw nuts. Metric series |
| BS EN 20273:1992 | Fasteners. Clearance holes for bolts and screws |
| BS EN 28673:1992 | Hexagon nuts, style 1, with metric fine pitch thread. Product grades A and B |
| BS 4395-2:1969 | Specification for high strength friction grip bolts and associated nuts and washers for structural engineering Higher grade bolts and nuts and general grade washers |
| ISO 554:1976 | Standard atmospheres for conditioning and/or testing — Specifications |
| BS EN 24032:1992 | Hexagon nuts, style 1. Product grades A and B |
| BS EN 28674:1992 | Hexagon nuts, style 2, with metric fine pitch thread. Product grades A and B |
Access your standards online with a subscription
Features
-
Simple online access to standards, technical information and regulations.
-
Critical updates of standards and customisable alerts and notifications.
-
Multi-user online standards collection: secure, flexible and cost effective.