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Grading and scaling regulations for forestry products
(sawlogs and pulpwood)

SAWLOGS

Developed by "Tømmermålingsforeningenes Fellesorgan" (TMF) and sanctioned by FUNT 12.03.98.
Effective 01.08.98.
Replacing "Forskrift for måling av skogvirke (hoveddel)
vedtatt av Tømmermålingsrådet 28. mai 1990".

LIST OF CONTENTS:

GRADING AND SCALING REGULATIONS FOR CONIFEROUS SAWLOGS
1. GRADING AND SCALING REGULATIONS
   1.1. Reception control
   1.2. Grading and scaling methods
   1.3. Log grading and scaling
      1.3.1. Conditions for log grading and scaling
   1.4. SWVM-grading and scaling
      1.4.1. Conditions for SWV –grading and scaling
      1.4.2. Quality classes and registration
2. LOG REQUIREMENTS
   2.1 General
   2.2. Quality classes
3. DIMENSIONS

Tolerance table EAST and NORTH

Tolerance table SOUTH and WEST

GRADING AND SCALING REGULATIONS FOR CONIFEROUS SAWLOGS.
Sawlogs are roundwood to be used as raw material for the production of timber.

1. GRADING AND SCALING REGULATIONS.

1.1. Reception control.

Reception control is performed according to rules laid down in Grading and scaling regulations for forestry products (sawlogs and pulpwood) general specifications, pt. 1.4.

1.2. Grading and scaling methods .

Coniferous sawlogs may be graded and scaled by log grading and scaling or by SWVM grading and scaling. Test sampling grading and scaling agreed by the parts and technically sanctioned by the grading association may be used.

1.3. Log grading and scaling.

1.3.1 Conditions for log grading and scaling.

When log scaling the volume is computed on the basis of the length of the single log and its diameter under bark.

Length is the shortest distance between the butt end and the top end of the log without considering ordinary undercut.

Diameter is to be measured as the average of the largest and the smallest diameter at a right angle to the length direction of the log, 10 cm from the top end. With unevenness at the measuring place, the diameter is being registered further in where it appears to be normal. By optical-electronical measuring, diameters are recorded in one or more directions.

When log grading and scaling, both ends of the log and at least 70 % of the cylindrical surface of the log are to be inspected. The part of the log not visible is presumed to display the same quality as the adjoining surfaces. When grading and scaling on a log haul conveyor, mirror arrangements or cameras are to be positioned so that the demands to inspection can be complied with. The 70 % limit is defined as the visible part of the logs circumference and is controlled on a suitable log with a diameter of 22 cm.

Prior to a log being recorded as being special the log is to be inspected more closely, even by stopping the conveyor if necessary.

1.4. SWVM grading and scaling.

1.4.1 Conditions for SWVM grading and scaling.

SWVM grading and scaling of sawlogs is only to be used for spruce (Picea abies). Pine (Pinus silvestris) may be included in the lot to be graded and scaled with up to 10% of the total volume, but is to be registered as spruce.

If more than 5 % of the net volume of the lot to be graded and scaled is judged to be pulpwood ("utlegg"), or more than 2 % is to be regarded as rejects, grading and scaling by the SWVM method is not to be used, unless this volume can be recorded with certainty.

1.4.2. Quality classes and registration.

The distribution per cent of the volumes of the quality classes first-class, second-class and pulpwood ("utlegg") deducted eventual rejects is to be recorded. The visible part of the object is regarded as representative for the whole unit.

Loads/lots damaged by wood-boring insects are rejected from SWVM grading and scaling unless seller and buyer agree that the delivery is to be graded and scaled according to a special agreement.

The number of logs in the lot, deducted rejects, is counted.

The volume of the average log is computed by dividing the net solid wood volume by number of logs. The volume-evaluated average length after eventual shortening is used to compute the top-diameter of the average log. The average log is used to calculate the value of approved assortments. Price for the average log is found by interpolation in mm for diameter and cm for length in the current price table, with eventual correction.

2. LOG REQUIREMENTS.

2.1. General.

Coniferous sawlogs are classified as the following species:

(Spruce) Norway spruce (Picea abies) and other spruce species as agreed.
(Pine) Scots pine (Pinus silvestris) and other pine species as agreed.

Coniferous sawlogs are delivered for grading and scaling either as a single species or in a mixture of species according to the contract.

The individual log is to be fit for sawing and is to be judged as it is presented for grading and scaling. The log shall be well pruned and be of agreed degree of freshness.

2.2. Quality classes.

By log grading and scaling, sawlogs are judged in Quality classes according to the criteria in the actual tolerance table. By SWVM grading and scaling it is referred to pt. 1.4.1.

3. DIMENSIONS.

If the parts have not agreed upon other dimension requirements the following applies:

DIMENSION TABLE
	Quality classes
	1. Special	2. First-class	3. Second-class
Minimum top-diameter under bark	22 cm	12 cm	12 cm
Maximum diameter under bark anywhere on the log	60 cm	60 cm	60 cm
Minimum length	34 dm	34 dm	34 dm
Maximum length	58 dm	58 dm	58 dm

	TOLERANCE TABLE EAST AND NORTH for coniferous sawlogs in different quality classes Permitted numbers of visible defects.
General	On an individual log only one defect of maximum extension is permitted. If there are more defects present, then these must be comparatively smaller. One single defect that according to the tolerance table should downgrade the log to a lower quality class may however be tolerated if the quality of the log otherwise is plainly above the lower limit of the class.
Tolerance defects	Defects closer than 15 cm to one of the log ends and surface defects smaller than 0.5 cm are to be regarded as tolerance defects. Tolerance defects are permitted only in one end of the log.
Abatements	Abatements may take place as: Length abatement (shortening) with up to 4 length units of each 3dm. After shortening the log shall satisfy the length- and quality-requirements of sawlogs. Diameter abatement with up to 3 diameter units of each 1 cm. After diameter abatement the log shall satisfy the diameter- and quality- requirements of sawlogs. Length- and diameter-abatement in combination can be performed on one log with a total of up to 4 units. Abatements may not be used to lift a log to a better quality class, but a pulpwood log that after abatement satisfies the quality- and dimension-requirements for sawlogs may be graded and scaled as such. The log is to be registered in the qualityclass that is satisfied by the permissible part of the log, but with abatement due to forest decay, the log is classified as second class. Length abatement is to be done when the defect is in the ends of the log and influences the top-diameter. Diameter abatement is to be done when the defect is in on the log and influences the top-cylinder. Both with abatement of length and diameter the whole of the defect is to be removed. Length abatement is done in units each of 3 dm. Diameter abatement is done in whole centimeters. Defects or parts of defects smaller than half a unit are tolerated apart from forest decay. A log that after abatement does not satisfy the requirements of second-class is registered as pulpwood when it satisfies the quality-requirements of first-class pulpwood as well as the agreed dimension requirements. A log that does not satisfy the requirements is to be rejected and the volume registered as for permitted assortments.
Definitions knots	Numbers and sizes apply for the knottiest 1.5 m section on the knottiest halfside of the log. The permitted number of knots must have an even distribution within the section. All knots are measured under bark at a right angle to the length of the log in a plane parallel to the log surface. Both heartwood and sapwood of the knot are included in the diameter. Knots smaller than the minimum sizes listed are not to be considered. Sound knot: Knot intergrown with the surrounding wood. Dead knot: Knot not intergrown with the surrounding wood. Rotten knot: Knot completely decayed.

Tolerance table EAST and NORTH

Type of defect	Dimension class in cm (under bark)	Quality classes
Type of defect	Dimension class in cm (under bark)	SPECIAL	FIRST CLASS	SECOND CLASS
Small knots	All	In addition to the defects mentioned below a corresponding number of sound/dead small knots are tolerated, i.e. knots with the smallest diameter less than the smallest knot diameter stated below for the respective diameterclasses.
Sound knots	18 cm or smaller	Not permitted	5 knots 2 – 2.5 cm	5 knots Spruce: 3 - 5 cm Pine: 4 - 6 cm
	19 - 27 cm	Not permitted	5 knots 2.5 - 3 cm	5 knots Spruce: 4 - 6 cm Pine: 5 - 7 cm
	28 cm and up	Not permitted	5 knots 3 – 3.5 cm	5 knots Spruce: 5 - 7 cm Pine: 6 - 8 cm
Dead knots (black knots) and barkringed knot	18 cm and smaller	Not permitted	5 knots 1 – 2 cm	5 knots 1.5 - 3 cm
	19 - 27 cm	Not permitted	5 knots 1.5 – 2.5 cm	5 knots 2.5 - 4 cm
	28 cm and up	Not permitted	5 knots 2 - 3 cm	5 knots 3.5 - 5 cm
Rotten knot	18 cm and smaller	Not permitted	1 knot max. 1.0 cm when log otherwise is of very good quality	3 knots 1.5 - 3 cm
	19 - 27 cm	Not permitted	1 knot max. 1.5 cm when log otherwise is of very good quality	3 knots 2.5 - 4 cm
	28 cm and up	Not permitted	1 knot max. 2.0 cm when log otherwise is of very good quality	3 knots 3.5 - 5 cm
Knot burrs (overgrown knot)	All	Not permitted	Up to 0,5 cm height above adjacent wood surface measured under bark. Knot burrs within the 1.5 m knottiest halfside are counted together with number of dead knots.	Larger than 0.5 cm height above adjacent wood surface measured under bark. Knot burrs within the 1.5 m knottiest halfside are counted together with number of dead knots.
Top rupture (spike knot)	All	Not permitted	Not permitted	1,0 cm, but without indication of crook linked to the knot

Tolerance table EAST and NORTH

Type of defect	Quality classes
Type of defect	SPECIAL	FIRST CLASS	SECOND CLASS
Long crook	Deflection max. 0.25 % of length	Deflection max. 0. 5 % of length	Deflection max. 1.0 % of length
Sharp crook	Not permitted	Not permitted	Not permitted
Angled crook	Not permitted	Not permitted	Permitted to top-cylinder
Butt crook	Not permitted	Not permitted	Permitted to top-cylinder
Double crook	Not permitted	Not permitted	Permitted to top-cylinder
Spiral crook	Not permitted	Not permitted	Permitted to top-cylinder
Forest decay	Not permitted	Not permitted	Not permitted
Loose rot in center	Not permitted	Not permitted	Not permitted
Anilincoloured wood	Not permitted	Not permitted	Permitted up to 1m length
Storage decay	Not permitted	Not permitted	Not permitted
Log stain	Not permitted	Not permitted	Permitted in single logs
Resinous wood	Not permitted	Not permitted	Permitted up to 1 m length on at most half the circumference
Compression wood (3 cm outside pith)	Not permitted	Permitted in an area corresponding to 4 annual rings in half the circumference, but not throughout.	Permitted in an area corresponding to 10 annual rings in half the circumference.
Pith shake	Not permitted	Not permitted	Not large and open. Maximum radial extension 5 cm.
Ring shake	Not permitted	Not permitted	Permitted in butt end with a diameter of up to 5 cm.
Annual rings and their width	Even and at least 20 in the interval from 2 cm to 8 cm from the pith in the butt end	Average in top-end at most 4 mm from 2 cm from pith and out. Largest ring width 6 mm.	Average in top-end at most 6 mm from 2 cm from pith and out. Largest ring width 10 mm.
Double pith	Not permitted	Not permitted	Not permitted
Bark pocket, not overgrown (influences top-cylinder)	Not permitted	Not permitted	Not permitted
Overgrown bark pocket	Not permitted	Not permitted	Pine: Permitted up to 5 dm length Spruce: Not permitted
Felling damage influencing the top-cylinder	Not permitted	Not permitted	Not permitted
Seasoning check from the ends.	Permitted up to 15 cm	Permitted up to 15 cm	Permitted up to 15 cm
Seasoning check from the surface of the bole	Permitted to top-cylinder	Permitted to top-cylinder	Permitted to top-cylinder
Damage by wood-boring insects, metal, stone, soot, fire-damaged wood.	Not permitted	Not permitted	Not permitted

	TOLERANCE TABLE SOUTH AND WEST for coniferous sawlogs in different quality classes Permitted numbers of visible defects.
General	On an individual log only one defect of maximum extension is permitted. If there are more defects present, then these must be comparatively smaller. One single defect that according to the tolerance table should downgrade the log to a lower quality class may however be tolerated if the quality of the log otherwise is plainly above the lower limit of the class.
Tolerance defects	Defects closer than 15 cm to one of the log ends and surface defects smaller than 0.5 cm are to be regarded as tolerance defects. Tolerance defects are permitted only in one end of the log.
Abatements	Abatements may take place as: Length abatement (shortening) with up to 2 length units of each 3dm for defects marked (LD). After shortening the log shall satisfy the length- and quality-requirements of sawlogs. Diameter abatement with up to 2 diameter units of each 1 cm for defects marked (DD). After diameter abatement the log shall satisfy the diameter- and quality- requirements of sawlogs. Only one type of abatement performed on one log. Abatements may not be used to lift a log to a better quality class, but a pulpwood log that after abatement satisfies the quality- and dimension-requirements for sawlogs may be graded and scaled as such. The log is to be registered in the qualityclass that is satisfied by the permissible part of the log, but with abatement due to forest decay, the log is classified as second class. Length abatement is to be done when the defect is in the ends of the log and influences the top-diameter. Diameter abatement is to be done when the defect is in on the log and influences the top-cylinder. Both with abatement of length and diameter the whole of the defect is to be removed. Length abatement is done in units each of 3 dm. Diameter abatement is done in whole centimetres. Defects or parts of defects smaller than half a unit are tolerated apart from forest decay. A log that after abatement does not satisfy the requirements of second-class is registered as pulpwood when it satisfies the quality-requirements of first-class pulpwood as well as the agreed dimension requirements. A log that does not satisfy the requirements is to be rejected and the volume registered as for permitted assortments.
Definitions knots	Numbers and sizes apply for the knottiest 1.5 m section on the knottiest halfside of the log. The permitted number of knots must have an even distribution within the section. All knots are measured under bark at a right angle to the length of the log in a plane parallel to the log surface. Both heartwood and sapwood of the knot is included in the diameter. Knots smaller than the minimum sizes listed are not to be considered. Sound knot: Knot intergrown with the surrounding wood. Dead knot: Knot not intergrown with the surrounding wood. Rotten knot: Knot completely decayed.

Tolerance table SOUTH and WEST

Type of defect
Quality classes

SPECIAL

FIRST CLASS

SECOND CLASS

Sound knots (LD)
Dead knots (black knots) and barkringed knot (LD)

Rotten knot (LD)

SUM

Sound, dead and rotten knots within limits above
Not permitted

Not permitted

Not permitted

0

2.5 - 4 cm

7 knots 1.5 – 3 cm

1 knot max. 1.5 cm when log otherwise is of very good quality

Maximum 10 knots, of which maximum 7 dead and 1 rotten

4 - 8 cm

7 knots 2-5 cm

3 knots 1.5 - 4 cm

Maximum 12 knots, of which maximum 7 dead and 3 rotten

Knot burrs (overgrown knot)
Not permitted

Permitted, counted as dead knots.

Permitted, counted as dead knots.

Top rupture (spike knot)
Not permitted
Not permitted

1.0 cm, but without indication of crook linked to the knot

Annual rings an their width
Even and at least 20 in the interval from 2 cm to 8 cm from the pith in the butt end

Average in top-end at most 4 mm from 2 cm from pith and out. Largest ring width 6 mm.

Average in top-end at most 6 mm from 2 cm from pith and out. Largest ring width 10 mm.

Compression wood (outside 3 cm from pith) Not permitted

Permitted in an area corresponding to 2 annual rings in half the circumference.

Permitted in an area corresponding to 10 annual rings in half the circumference.

Butt crevices
Permitted to top-cylinder

Permitted

Permitted

Buttresses
Maximum 10 cm over 20 cm

Maximum 10 cm over 20 cm

Maximum 10 cm over 20 cm

Long crook
Deflection max.
0.5 % of length

Deflection max.
0.5 % of length

Deflection max.
1.0 % of length

Sharp crook
Not permitted

Not permitted

Not permitted

Angled crook (LD) or (DD)
Not permitted

Not permitted

Permitted to top-cylinder

Butt crook (LD) or (DD)
Not permitted

Not permitted

Permitted to top-cylinder

Double crook (LD) or (DD)
Not permitted

Not permitted

Permitted to top-cylinder

Spiral crook (LD) or (DD)
Not permitted

Not permitted

Permitted to top-cylinder

Tolerance table SOUTH and WEST

Type of defect
Quality classes

SPECIAL

FIRST CLASS

SECOND CLASS

Storage decay
Not permitted

Not permitted

Not permitted

Log stain
Not permitted

Not permitted

Permitted in single logs

Surface stain Not permitted

Permitted

Permitted

Forest decay in small area
(LD in second class)

Not permitted

Not permitted

Not permitted (LD)

Loose decay in center can not be (LD)

Loose decay in center
Not permitted

Not permitted

Not permitted

Anilincoloured wood
Forest decay outside top-cylinder

Not permitted

Not permitted

Permitted up to 0.6 m length

Resinous wood (LD)
Not permitted

Not permitted

Not permitted

Pith shake (LD)
Not permitted

Not permitted

Not permitted

Ring shake
Not permitted

Not permitted

Not permitted

Double pith
Not permitted

Not permitted

Not permitted

Open bark pocket in pine with dry resinous wood (LD or DD)

Not permitted

Permitted to top-cylinder

Permitted to top-cylinder

Overgrown bark pocket in pine

Not permitted

Not permitted
(Downgraded special due to overgrown bark pocket is permitted)

Permitted without abatement

Bark pockets in spruce
Not permitted

Not permitted

Not permitted

Felling damage influencing the top-cylinder (LD or DD)

Not permitted

Not permitted

Not permitted

Seasoning check (LD)
Permitted up to 15 cm

Permitted up to 15 cm

Permitted up to 15 cm

Damage by wood-boring insects, metal, stone, soot, fire-damaged wood.

Not permitted

Not permitted

Not permitted

TOLERANCE TABLE EAST AND NORTH

TOLERANCE TABLE SOUTH AND WEST