BS 4978:1996
Superseded
A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.
A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.
Specification for visual strength grading of softwood
Hardcopy , PDF
05-31-2007
English
08-15-1996
Foreword
Specification
1 Scope
2 References
3 Definitions
4 Strength graded timber
5 Measurement of characteristics
6 Grade requirements
7 Marking
Annexes
A (normative) Determination of the knot area ratio in
cases of dispute
B (normative) The control and supervision of strength
grading operations
C (normative) Determination of slope of grain
D (informative) Species marking
Table
1 Permissible limits for the GS and SS visual strength
grades
Figures
1 Edge, face and margin areas
2 Knot projection
3 Typical knot area rations and the resulting grades
4 Measurement of rate of growth
5 Amounts of wane
6 Measurement of bow, spring and twist
7 Example of a mark on visually strength graded softwood
C.1 Swivel handled scribe for determination of slope of
grain
C.2 Use of scribe
C.3 Measurement of slope of grain
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