NF EN 20898-1 : 1991

Cooperating organizations
National foreword
Foreword
1. Scope and field of application
2. References
3. Designation system
4. Materials
5. Mechanical properties
6. Mechanical properties to be determined
7. Minimum ultimate tensile loads and proofing loads
8. Test methods
9. Marking
Annex
Properties at elevated temperature
Tables
1. System of coordinates
2. Steels
3. Mechanical properties of bolts, screws and studs
4. Key to test programmes
5. Test programmes A and B for acceptance purposes
6. Minimum ultimate tensile loads - ISO metric coarse
     pitch thread
7. Proofing loads - ISO metric coarse pitch thread
8. Minimum ultimate tensile loads - ISO metric fine
     pitch thread
9. Proofing loads - ISO metric fine pitch thread
10. Hole diameters for wedge loading test
11. Wedge dimensions
12. Values of angle beta
13. Values for H1 and E
14. Marking symbols
15. Identification marks for studs
16. Properties at elevated temperature
Figures
1. Test piece for tensile test
2. Application of proofing load to full-size bolts
3. Wedge loading of full-size bolts
4. Head soundness test
5. Zones of decarburization
6. Hardness measurements for decarburization test
7. Examples of marking on hexagon bolts and screws
8. Examples of marking on hexagon socket head cap screws
9. Marking of stud
10. Left-hand thread marking
11. Alternative left-hand thread marking
National annex NA (informative)
National annex NB (informative)

Describes the mechanical properties of bolts, screws and studs when tested at room temperature. Applies to bolts, screws and studs with nominal thread diameter less than 39mm, with triangular ISO thread, with diameter/pitch combinations according to ISO 261 and ISO 262, with thread tolerance according to ISO 965-1 and ISO 965-2, of any shape and made of carbon or alloy steel. Does not apply to set screws and similar threaded fasteners.