Structural timber - Visual strength grading of tropical hardwood

This European Standard specifies a method of strength grading tropical hardwood visually for structural use.
The permissible limits of characteristics for a single visual strength grade of timber are specified, designated “Structural Tropical Hardwood” (STH) grade.
The method is only suitable for pieces of timber with a rectangular cross-section that is constant along their lengths.
Characteristics related to durability are not covered in this standard. For some end uses, additional requirements may be specified at the time of grading, e.g. sapwood exclusion.

Bauholz für tragende Zwecke - Visuelle Sortierung von Tropenholz nach der Festigkeit

Diese Europäische Norm legt ein Verfahren zur visuellen Festigkeitssortierung von Tropenholz für tragende Zwecke fest.
Die für eine visuelle Festigkeitsklasse zulässigen Grenzwerte der Eigenschaften werden festgelegt und als Sortierklasse "Tropenholz für tragende Zwecke" ("Structural Tropical Hardwood" (STH)) bezeichnet.
Das Verfahren ist ausschließlich für Holzstücke mit einem über die gesamte Länge gleich bleibenden rechtwinkligen Querschnitt geeignet.
Merkmale, die die Dauerhaftigkeit betreffen, sind nicht Gegenstand dieser Norm. Für einige Endanwendungen dürfen zusätzliche Anforderungen zum Zeitpunkt der Sortierung, z. B. Ausschluss von Splintholz, festgelegt werden.

Bois de structure - Classement visuel des bois feuillus tropicaux de structure

La présente Norme européenne spécifie une méthode permettant de classer visuellement les bois feuillus tropicaux selon leur résistance en vue d'un usage structurel.
Les limites admissibles des critères sont spécifiées pour une classe visuelle unique de résistance de bois feuillus tropicaux de structure appelée (STH) « Bois feuillus tropicaux de structure ».
La méthode spécifiée n'est applicable qu'aux pièces de bois de section rectangulaire constante sur toute la longueur.
Les caractéristiques liées à la durabilité ne sont pas couvertes par cette norme. Pour certaines utilisations, des exigences complémentaires peuvent être indiquées au moment du classement, par exemple l’exclusion de l’aubier.

Konstrukcijski les - Vizualno razvrščanje tropskega lesa po trdnosti

Ta dokument določa metodo vizualnega razvrščanja tropskega lesa po trdnosti za uporabo pri konstrukcijah. Ta metoda je primerna samo za kose lesa s pravokotnim prečnim prerezom, ki je stalen po njihovi dolžini.

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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.VWLBauholz für tragende Zwecke - Visuelle Sortierung von Tropenholz nach der FestigkeitBois de structure - Classement virtuel des bois feuillus tropicaux de structureStructural timber - Visual strength grading of tropical hardwood79.040Les, hlodovina in žagan lesWood, sawlogs and sawn timberICS:Ta slovenski standard je istoveten z:EN 16737:2016SIST EN 16737:2016en,fr,de01-julij-2016SIST EN 16737:2016SLOVENSKI
EN 16737
t r s x ICS
y {ä r v r English Version
Structural timber æ Visual strength grading of tropical hardwood Bois de structure æ Classement visuel des bois feuillus tropicaux de structure
Bauholz für tragende Zwecke æ Visuelle Sortierung von Tropenholz nach der Festigkeit This European Standard was approved by CEN on
s { March
t r s xä
egulations which stipulate the conditions for giving this European Standard the status of a national standard without any alterationä Upætoædate lists and bibliographical references concerning such national standards may be obtained on application to the CENæCENELEC Management Centre or to any CEN memberä
translation under the responsibility of a CEN member into its own language and notified to the CENæCENELEC Management Centre has the same status as the official versionsä
CEN members are the national standards bodies of Austriaá Belgiumá Bulgariaá Croatiaá Cyprusá Czech Republicá Denmarká Estoniaá Finlandá Former Yugoslav Republic of Macedoniaá Franceá Germanyá Greeceá Hungaryá Icelandá Irelandá Italyá Latviaá Lithuaniaá Luxembourgá Maltaá Netherlandsá Norwayá Polandá Portugalá Romaniaá Slovakiaá Sloveniaá Spainá Swedená Switzerlandá Turkey and United Kingdomä
CEN-CENELEC Management Centre:
Avenue Marnix 17,
B-1000 Brussels
t r s x CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Membersä Refä Noä EN
s x y u yã t r s x ESIST EN 16737:2016

European foreword . 3 1 Scope . 4 2 Normative references . 4 3 Terms and definitions . 4 4 Strength graded timber. 6 4.1 Supervision of strength grading operations. 6 4.2 Sizes . 6 4.3 Processing of visually graded timber. 6 4.4 Moisture content . 6 5 Measurement of strength-reducing characteristics . 7 5.1 Knots . 7 5.1.1 General . 7 5.1.2 Knot size: requisite comparisons . 7 5.1.3 Pin knots . 10 5.2 Slope of grain . 10 5.3 Density . 11 5.4 Fissures . 11 5.5 Wane . 11 5.6 Distortion . 11 5.6.1 Bow and spring . 11 5.6.2 Twist . 11 5.7 Biological characteristics . 11 5.7.1 Fungal biodegradation . 11 5.7.2 Insect attack . 12 5.7.3 Marine borers . 12 5.8 Other defects and characteristics . 12 6 Limiting values of characteristics for STH grade . 13 7 Marking . 13 Annex A (informative)
Tropical hardwood species and their densities . 14
to 100 mm, or; b) 10 mm for dimensions > 100 mm. Where graded timber is reduced in cross section beyond the above limits, it shall be re-graded if it is to conform to this standard. Where graded timber is reduced in length, or a piece of graded timber is cross-cut into two or more pieces, each resulting piece may be assumed to conform to the permissible limits of characteristics in Table 1 of this standard. 4.4 Moisture content Dry graded timber shall have at the time it is graded for fissures and distortion a mean moisture content of 20 % or less with no individual measurement exceeding 24 %. NOTE The end use determines whether timber needs to be dry graded or not. If timber is not dry graded, it may be needed to check fissures and distortion also at the time of end use. SIST EN 16737:2016

c) 2
f) Figure 1 — Measuring knot sizes 1 on faces and 2 on edges 5.1.2 Knot size: requisite comparisons For knots that are contained entirely within a single face or edge, the size of the knot shall be compared to the full size of the face or edge in which it appears (Figure 2). SIST EN 16737:2016

X is related to the thickness t and Y is compared to the width w. Figure 2 — Measuring knot sizes For arris knots that are not elonga

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