Log Grade Specification

Log
Grade
Small end
Diameter
(mm)
Maximum
Large end
Diameter
(mm)
Maximum
Knot size
(mm)
Length
(m)
Percentage
allowed
Sweep
Pruned peelers 300+ No limit 0 4.0, 6.0 Shippers option d/4
Japan A 200-340 800 d/3 up to 150 mm max
Excessive number of large knots not permitted
4.0
8.0
12.0
10% max
balance
50% min
d/4
d/2
d
Japan J 200-260 No limit d/3 up to 150 mm max
Excessive number of
large knots not permitted
4.0
8.0
12.0
10% max
balance
50% min
d/4
d/2
d
Korea K 200-260 No limit d/3 up to 150 mm max
Excessive number of
large knots not permitted
3.6
5.4
7.3
11.0
balance
10% max
balance
40% min
d/4
d/4
d/2
d
Pulp (Japan) 100+ No limit No limit 4.0, 6.0,
8.0
Shipper's option No limit

Note: d = small end diameter

For export grades, small end diameter is measured at the wharf under the Japanese Agricultural Standard (JAS) convention, i.e., rounded down to the nearest even two-centimetre interval.

Domestic Log Grades (Forest Research Specification)

Log Grade Log
status
Small end
Diameter
(mm)
Maximum
Knot
(mm)
Sweep
class
P1 Pruned 400+ 0 1
P2 Pruned 300-399 0 1
S1 Unpruned 400+ 60 1
S2 Unpruned 300-399 60 1
S3 Pruned or unpruned 200-299 60 1
L1 Unpruned 400+ 140 1
L2 Unpruned 300-399 140 1
L3 Unpruned 200-299 140 1
Pulp Unpruned 100 n/a 2

 

Maximum Permissible Sweep*:
Length <3.7 3.7-4.8 4.9-7.6 >7.6
Class1 d/8 d/4 d/3 d/2
Class2 d 2d 3d 4d

Source: Forest Research

Note: d = small end diameter
* Sweep is the maximum deviation from straightness along the length of the log.

 

Last Updated: 26 November 2010

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