What are the grades for veneer logs specified in this standard?

Logs are graded as Grade A, Grade B, and Grade C based on the type and extent of permissible defects (Clause 6).

What is the minimum length required for a log to be used for sliced veneer?

The minimum length is 1.2 meters, with a positive tolerance of 5 cm and no negative tolerance (Clause 7.1).

What is the minimum girth for a veneer log?

The minimum girth at the smaller end, over bark, shall be 90 cm (Clause 7.2).

Are knots allowed in Grade A logs?

Yes, up to two sound and live knots not exceeding 2.5 cm in diameter are permissible for Grade A logs (Table 2).

IS 15457

: 2004

Logs for production of sliced veneers

CurrentSpecializedSpecificationMaterials Science · Timber and Timber Stores

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This standard specifies the requirements for logs of various timber species intended for the production of sliced veneers. It covers terminology, general quality requirements, grading criteria based on defects, and prescribes dimensions and tolerances to ensure raw material quality for the veneer industry.

Logs for production of sliced veneers

Quick Reference Values

Minimum log length1.2 m

Tolerance on log length+5 cm (no negative tolerance)

Minimum log girth (at smaller end)90 cm

Maximum permissible sweep5 cm per metre length

Permissible heart rot for Grade ANil

Permissible knots (sound & live) for Grade AUp to 2 knots not exceeding 2.5 cm diameter

Practical Notes

Grading is the most critical aspect, directly impacting the quality and price of the veneer. Grade A logs are nearly free of defects.

Proper identification of timber species as listed in Annex A is the first step before procurement.

Pay close attention to defects like knots, splits, and sweep, as their limits are strictly defined per grade in Table 2.