DOCSLIB.ORG

Janka Hardness Using Nonstandard Specimens

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

United States Department of Agriculture Janka Hardness Using Forest Service Nonstandard Specimens Forest Products Laboratory Research David W. Green Note Marshall Begel FPL–RN–0303 William Nelson Abstract Contents Janka hardness determined on 1.5- by 3.5-in. specimens Executive Summary ............................................................. i (2×4s) was found to be equivalent to that determined using Introduction ..........................................................................1 the 2- by 2-in. specimen specified in ASTM D 143. Data are Background ..........................................................................1 presented on the relationship between Janka hardness and History of Standardization ...............................................1 the strength of clear wood. Analysis of historical data de- Relationship of Janka Hardness to Other Properties ........2 termined using standard specimens indicated no difference Strength Properties .......................................................2 between side hardness values determined on the radial face Specific Gravity ...........................................................3 as opposed to the tangential. Analysis of historical data also Load Placement and Specimen Thickness ...................4 indicated that the relationship between hardness modulus Growth Ring Orientation .............................................4 (HM) and Janka hardness (H) may be different for hardwood Moisture Content .........................................................5 species than for softwood. Recommendations are given Hardness Modulus .......................................................6 for ensuring that experimental procedures do not bias the Procedures ............................................................................9 results when testing non-standard specimens. The authors Material ............................................................................9 caution that if hardness (ASTM D 143) and hardness modu- Testing ............................................................................10 lus (ASTM D 1037) are measured simultaneously for each Results and Discussion ......................................................10 ball penetration, the HM /H ratio may be different than that Janka Hardness ...............................................................10 given in D 1037 because the two standards specify different Validity of Individual Values ......................................10 rates of penetration. Analysis of Results ....................................................11 Janka Hardness and Hardness Modulus .........................11 Keywords: Janka hardness, hardness modulus, Douglas-fir, Conclusions ........................................................................12 2×4 References ..........................................................................13 Metric conversion chart Inch–pound unit Conversion factor SI unit Acknowledgments inch (in.) 25.4 millimeter Funding for this study was provided by the Forest Products pound (lb) 0.454 kilogram Laboratory. The authors acknowledge the assistance of Tim- pound–force (lbf) 0.27 Newton othy Nelson of the Forest Products Laboratory for specimen temperature ºF (T − 32)/1.8 temperature ºC F preparation and testing. February 2006 Green, David W.; Begel, Marshall; Nelson, William. 2006. Janka hardness using nonstandard specimens. Research Note FPL-RN-0303. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Labora- tory. 13 p. A limited number of free copies of this publication are available to the public from the Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI 53726–2398. This publication is also available online at www.fpl.fs.fed.us. Laboratory publications are sent to hundreds of libraries in the United States and elsewhere. The Forest Products Laboratory is maintained in cooperation with the University of Wisconsin. This article was written and prepared by U.S. Government employees on official time, and it is therefore in the public domain and not subject to copyright. The use of trade or firm names in this publication is for reader information and does not imply endorsement by the United States Department of Agriculture (USDA) of any product or service. The USDA prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orienta- tion, genetic information, political beliefs, reprisal, or because all or a part of an individual’s income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program informa- tion (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at (202) 720–2600 (voice and TDD). To file a complaint of discrimi- nation, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250–9410, or call (800) 795–3272 (voice) or (202) 720–6382 (TDD). USDA is an equal opportunity provider and employer. Executive Summary may effect hardness values and should thus be avoided. We also found that when using an automated routine to select Background load and deformation points off a continuous electronic re- The Janka ball hardness test has been specified for solid cord, it is important to ensure that the load reported for hard- wood in ASTM standard D 143 since 1922. The standard ness corresponds very closely to a deformation of 0.222 in. calls for a specimen with a cross section of 2 by 2 in. Un- For all thickness values, the data indicated a ratio of hard- like the tests for some properties, this standard does not ness modulus to Janka hardness (HM /H) of 4.9 as opposed provide an alternative size of 1 by 1 in. The standard also to the value of 5.4 given in ASTM D 1037. This difference requires tests on the radial and tangential faces of the speci- was attributed to two factors. First, the D 1037 ratio was men, with the average of the values obtained reported as originally developed by combining data for softwood and the hardness of the specimen. The study presented here was hardwood species. A reanalysis of the historical data indi- prompted by our concerns about the results obtained when cated that whereas a ratio of 5.3 is appropriate for hardwood conducting Janka hardness tests on non-standard specimens. species, the ratio for softwood species should be 4.4. Sec- Hardness tests had been conducted on 1.5- by 3.5-in. speci- ond, the rate of loading specified for Janka hardness in both mens (2×4s) as part of a study of the properties of lumber D 143 and D 1037 is 0.25 in/min, whereas D 1037 specifies cut from small-diameter Douglas-fir trees growing in dense a rate of 0.05 in/min for determining hardness modulus. stands. These two properties can be determined by current specifi- cations only by making two separate indentations for each Objectives property. In our tests, both Janka hardness and hardness Our primary objective was to evaluate hardness values modulus were measured on one indentation, using a rate of determined from tests on 1.5-in.-thick 2×4s compared to indentation of 0.25 in/min and resulted in an HM /H ratio of values that would have been obtained on standard 2-in.- about 4.9. We speculate that had we determined hardness thick specimens. The study included determining the effect modulus at a rate of loading five times slower, then the ratio of thickness on Janka hardness as well as a critical analysis of hardness to hardness modulus would have been lower and of historical data and information on various factors that more in line with the expected result. might affect Janka hardness. Our secondary objective was to provide additional information about the relationship be- Conclusions tween Janka hardness and the hardness modulus specified in From our test results and a critical review of existing litera- ASTM D 1037. ture we conclude the following: Procedures • Hardness values can be determined for 2×4s that are Hardness tests were conducted using indentations on the equivalent to those that would have been obtained by us- wide face of 2×4s at thickness values of 1, 1.5, and 3 in. ing the standard 2- by 2- by 6-in. specimen of ASTM The 1-in. data were obtained by planing the 1.5-in. 2×4 on D 143. the side opposite the indentations; the 3-in. results were ob- • If two pieces must be used to obtained a desired thickness, tained by either “stacking” the specimen to be tested on top the pieces should be glued together. of another 2×4 or by “gluing” the 2×4 to be tested to another • Continuous recording of load and deflection offers oppor- 2×4. The test set-up allowed continuous recording of load as tunities to better understand the results of Janka hardness a function of penetration depth of the standard 0.444-in.-di- tests on wood products, but care must be taken to ensure ameter steel ball into the specimen. Since hardness modulus that the load reported is actually that at 0.222-in. is simply the relationship between the slope of the load and deformation. the penetration depth, it was possible to obtain both Janka • There is no significant difference between hardness deter- hardness and hardness modulus from the same indentation. mined on the radial face as opposed to that determined on the tangential face, even for oak. Results • Reanalysis of historical data indicates
Recommended publications
  • Genetic and Phenotypic Characterization of Figured Wood in Poplar

    Genetic and Phenotypic Characterization of Figured Wood in Poplar

    Genetic and Phenotypic Characterization of Figured Wood in Poplar Youran Fan1,2, Keith Woeste1,2, Daniel Cassens1, Charles Michler1,2, Daniel Szymanski3, and Richard Meilan1,2 1Department of Forestry and Natural Resources, 2Hardwood Tree Improvement and Regeneration Center, and 3Department of Agronomy; Purdue University, West Lafayette, Indiana 47907 Abstract Materials and Methods When “Curly Aspen” (Populus canescens) was first Preliminary Results characterized in the early 1940’s[1], it attracted the attention from the wood-products industry because Genetically engineer commercially 1) Histological sections reveal that “Curly Aspen” has strong “Curly Aspen” produces an attractive veneer as a important trees to form figure. ray flecks (Fig. 10) but this is not likely to be responsible result of its figured wood. Birdseye, fiddleback and for the figure seen. quilt are other examples of figured wood that are 2) Of the 15 SSR primer pairs[6, 7, 8] tested, three have been commercially important[2]. These unusual grain shown to be polymorphic. Others are now being tested. patterns result from changes in cell orientation in Figure 6. Pollen collection. Branches of Figure 7. Pollination. Branches Ultimately, our genetic fingerprinting technique will allow “Curly Aspen” were “forced” to shed collected from a female P. alba us to distinguish “Curly Aspen” from other genotypes. the xylem. Although 50 years have passed since Figure 1. Birdseye in maple. pollen under controlled conditions. growing at Iowa State University’s finding “Curly Aspen”, there is still some question Rotary cut, three-piece book McNay Farm (south of Lucas, IA). 3) 17 jars of female P. alba branches have been pollinated match (origin: North America).
  • Comparative Study of NZ Pine & Selected SE Asian Species

    Comparative Study of NZ Pine & Selected SE Asian Species

    (FRONT COVER) A COMPARATIVE STUDY OF NEW ZEALAND PINE AND SELECTED SOUTH EAST ASIAN SPECIES (INSIDE FRONT COVER) NEW ZEALAND PINE - A RENEWABLE RESOURCE NZ pine (Pinus radiata D. Don) was introduced to New Zealand (NZ) from the USA about 150 years ago and has gained a dominant position in the New Zealand forest industry - gradually replacing timber from natural forests and establishing a reputation in international trade. The current log production from New Zealand forests (1998) is 17 million m3, of which a very significant proportion (40%) is exported as wood products of some kind. Estimates of future production indicate that by the year 2015 the total forest harvest could be about 35 million m3. NZ pine is therefore likely to be a major source of wood for Asian wood manufacturers. This brochure has been produced to give prospective wood users an appreciation of the most important woodworking characteristics for high value uses. Sponsored by: Wood New Zealand Ltd. Funded by: New Zealand Ministry of Foreign Affairs and Trade Written by: New Zealand Forest Research Institute Ltd. (Front page - First sheet)) NEW ZEALAND PINE - A VERSATILE TIMBER NZ pine (Pinus radiata D.Don) from New Zealand is one of the world’s most versatile softwoods - an ideal material for a wide range of commercial applications. Not only is the supply from sustainable plantations increasing, but the status of the lumber as a high quality resource has been endorsed by a recent comparison with six selected timber species from South East Asia. These species were chosen because they have similar end uses to NZ pine.
  • Properties of Western Larch and Their Relation to Uses of the Wood

    Properties of Western Larch and Their Relation to Uses of the Wood

    TECHNICAL BULLETIN NO. 285 MARCH, 1932 PROPERTIES OF WESTERN LARCH AND THEIR RELATION TO USES OF THE WOOD BY R. P. A. JOHNSON Engineer, Forest Products Laboratory AND M. I. BRADNER In Charge^ Office of Forest Products y Region I Branch of Research, Forest Service UNITED STATES DEPARTMENT OF AGRICULTURE, WASHINGTON, D. C. TECHNICAL BULLETIN NO. 285 MARCH, 1932 UNITED STATES DEPARTMENT OF AGRICULTURE WASHINGTON, D. C. PROPERTIES OF WESTERN LARCH AND THEIR RELATION TO USES OF THE WOOD By R. P. A. JOHNSON, Engineer, Forest Products Laboratory^^ and M. I. BRADNER, in Charge, Office of Forest Products, Region 1, Branch of Research, Forest Service * CONTENTS Page Page Introduction 1 Mechanical and physical properties—Con. The larch-fir mixture 2 Resistance to decay, weathering, and Character and range of the western larch insects 39 forest __ 4 Reaction to preservative treatment 42 Occurrence 4 Heat and insulating properties 42 Character 4 Permeability by liquids 42 Size of stand 7 Tendency to impart odor or ñavor___:. _. 43 Cut and supply 9 Tendency to leach or exude extractives. _ 43 Merchandising practices 10 Chemical properties 43 distribution lO Fire resistance ., 43 Percentage of cut going into various lum- Characteristic defects of western larch 44 ber items 12 Natural defects 44 Descriptive properties of western larch 13 Seasoning defects 46 General description of the wood 13 Manufacturing defects 47 Heartwood content of lumber 13 Grades and their characteristics 47 Growth rings 14 Grade yield and production 48 Summer-wood content 14 Heartwood content 50 Figure. 14 Width of rings 50 How to distinguish western larch from other Grade descriptions .
  • Oak, Pine & Hemlock Silviculture

    Oak, Pine & Hemlock Silviculture

    Pine‐Oak‐Hemlock‐‐Silviculture Institute 7/18/2017 Some Standard Silvicultural Methods • 1. Single‐tree selection • 2. Group \patch: includes group release and shelterwood groups • 3. Clearcutting • 4. Overstory removal Oak, Pine & Hemlock Silviculture • 5. Standard shelterwood • 6. Low‐density shelterwood • 7. Deferred shelterwood • 8. Irregular shelterwood W.B. Leak • 9.Precommercial thinning • 10. Commercial thinning • 11. Stand improvement • 12. Rehabilitation • 13. Ecological forestry • 14. Natural disturbance silviculture App. Percent Cu. Vol. and Sapling Numbers In New Hampshire Major Oak/Pine Silvi Problems • Species Vol. % Sapling % • Regen • Red oak 8.9 3.2 • White Pine 20.2 3.4 • Red Maple 14.6 11.9 • Regen • Regen 1 Pine‐Oak‐Hemlock‐‐Silviculture Institute 7/18/2017 Where Does Oak/Pine/Hemlock Like to Sources of Regen Problems Grow? Dry Sites: • Seed supply? Outwash • Seed losses? Shallow Bedrock • Germination? Sandy Tills • Browsing? • Competition? Hemlock: also on shallow, wet pan • All of the above!! 2 Pine‐Oak‐Hemlock‐‐Silviculture Institute 7/18/2017 Also: Old‐Field Pine A long history of white pine invasion of abandoned old‐fields on a variety of soils! Why?? Pine can handle eroded soils and grass/hay competition. Then…..After the Pine Harvest • Understory oak (a wildlife influence?) develops into a fine stand. Some of our best oak stands developed after pine (McKinnon 1935, Harv. Bull. 18). • But even after a careful oak shelterwood, the oak does not readily regenerate. • On some sites (e.g. sandy), pine regenerates under the oak – possibly another wildlife influence. 3 Pine‐Oak‐Hemlock‐‐Silviculture Institute 7/18/2017 The Oak/Pine Regeneration Process • Develops best from advanced regen.
  • Susceptibility of Larch, Hemlock, Sitka Spruce, and Douglas-Fir to Phytophthora Ramorum1

    Susceptibility of Larch, Hemlock, Sitka Spruce, and Douglas-Fir to Phytophthora Ramorum1

    Proceedings of the Sudden Oak Death Fifth Science Symposium Susceptibility of Larch, Hemlock, Sitka Spruce, and 1 Douglas-fir to Phytophthora ramorum Gary Chastagner,2 Kathy Riley,2 and Marianne Elliott2 Introduction The recent determination that Phytophthora ramorum is causing bleeding stem cankers on Japanese larch (Larix kaempferi (Lam.) Carrière) in the United Kingdom (Forestry Commission 2012, Webber et al. 2010), and that inoculum from this host appears to have resulted in disease and canker development on other conifers, including western hemlock (Tsuga heterophylla (Raf.) Sarg.), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), grand fir (Abies grandis (Douglas ex D. Don) Lindl.), and Sitka spruce (Picea sitchensis (Bong.) Carrière), potentially has profound implications for the timber industry and forests in the United States Pacific Northwest (PNW). A clearer understanding of the susceptibility of these conifers to P. ramorum is needed to assess the risk of this occurring in the PNW. Methods An experiment was conducted to examine the susceptibility of new growth on European (L. decidua Mill.), Japanese, eastern (L. laricina (Du Roi) K. Koch), and western larch (L. occidentalis Nutt.); western and eastern hemlock (T. canadensis (L.) Carrière); Sitka spruce; and a coastal seed source of Douglas-fir to three genotypes (NA1, NA2, and EU1) of P. ramorum in 2011. In 2012, a similar experiment was conducted using only the four larch species. Container-grown seedlings or saplings were used in all experiments. Five trees or branches of each species were inoculated with a single isolate of the three genotypes by spraying the foliage with a suspension of zoospores (105/ml).
  • Comparison of Oak and Sugar Maple Distribution and Regeneration in Central Illinois Upland Oak Forests

    Comparison of Oak and Sugar Maple Distribution and Regeneration in Central Illinois Upland Oak Forests

    COmparisON OF OaK AND Sugar MAPLE DistriBUTION AND REGENEratiON IN CEntral ILLINOIS UPLAND OaK FOREsts Peter J. Frey and Scott J. Meiners1 Abstract.—Changes in disturbance frequencies, habitat fragmentation, and other biotic pressures are allowing sugar maple (Acer saccharum) to displace oak (Quercus spp.) in the upland forest understory. The displacement of oaks by sugar maples represents a major management concern throughout the region. We collected seedling microhabitat data from five upland oak forest sites in central Illinois, each differing in age class or silvicultural treatment to determine whether oaks and maples differed in their microhabitat responses to environmental changes. Maples were overall more prevalent in mesic slope and aspect positions. Oaks were associated with lower stand basal area. Both oaks and maples showed significant habitat partitioning, and environmental relationships were consistent across sites. Results suggest that management intensity for oak in upland forests could be based on landscape position. Maple expansion may be reduced by concentrating mechanical treatments in expected areas of maple colonization, while using prescribed fire throughout stands to promote oak regeneration. INTRODUCTION Historically, white oak (Quercus alba) dominated much of the midwestern and eastern U.S. hardwood forests (Abrams and Nowacki 1992, Franklin et al. 1993). Oak is classified as an early successional forest species, and many researchers agree that oak populations were maintained by Native American or lightning-initiated fires (Abrams 2003, Abrams and Nowacki 1992, Hutchinson et al. 2008, Moser et al. 2006, Nowacki and Abrams 2008, Ruffner and Groninger 2006, Shumway et al. 2001). These periodic low to moderate surface fires favored the ecophysiological attributes of oak over those of fire-sensitive, shade-tolerant tree species, thereby continually resetting succession and allowing oaks and other shade-intolerant species to persist in both the canopy and understory (Abrams 2003, Abrams and Nowacki 1992, Crow 1988, Franklin et al.
  • Performance, Technology and Application of High Performance Marine Vessels Volume One

    Performance, Technology and Application of High Performance Marine Vessels Volume One

    Performance, Technology and Application of High Performance Marine Vessels Volume One Performance, Technology and Application of High Performance Marine Vessels Volume One Edited by Liang Yun, Raju Datla and Xinfa Yang Performance, Technology and Application of High Performance Marine Vessels Volume One Edited by Liang Yun, Raju Datla and Xinfa Yang This book first published 2018 Cambridge Scholars Publishing Lady Stephenson Library, Newcastle upon Tyne, NE6 2PA, UK British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Copyright © 2018 by Liang Yun, Raju Datla, Xinfa Yang and contributors All rights for this book reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the copyright owner. ISBN (10): 1-5275-0356-9 ISBN (13): 978-1-5275-0356-4 CONTENTS Preface by the Editors-in-Chief ................................................................. xii Liang Yun, Raju Datla, Xinfa Yang Preface .................................................................................................... xxiv Trevor Blakeley Preface .................................................................................................... xxvi Guo Da-cheng Preface .................................................................................................. xxviii Huang Ping-tao Preface ....................................................................................................
  • Sugar Maple - Oak - Hickory Forest State Rank: S3 - Vulnerable

    Sugar Maple - Oak - Hickory Forest State Rank: S3 - Vulnerable

    Sugar Maple - Oak - Hickory Forest State Rank: S3 - Vulnerable Mesic Forest (RMF): Sugar Maple - Oak - Hickory Forests are most occurrences of RMF diverse forests in central and eastern in Massachusetts are west Massachusetts where conditions, of the Connecticut River including nutrient richness, support Valley. The presence of Northern Hardwood species mixed with multiple species of species of Oak - Hickory Forests; hickories and oaks in SMOH is a main The herbaceous layer varies from sparse difference between these to intermittent, with sparse spring two types. Broad-leaved ephemerals that may include bloodroot or Woodland-sedge is close trout-lily. Later occurring species may to being an indicator of include wild geranium, herb Robert, wild SMOH. RMF is Rock outcrops in the spring in Sugar Maple - licorice, maidenhair fern, bottlebrush Oak - Hickory Forest area. Photo: Patricia characterized by very Swain, NHESP. grass, and white wood aster. Broad- dense herbaceous growth of spring leaved, semi-evergreen broad-leaved ephemerals; SMOH shares some of the Description: Sugar Maple - Oak - woodland-sedge is close to an indicator of species but with fewer individuals of Hickory Forests occur in or east of the the community. Witch hazel, hepaticas, fewer species. SMOH has evergreen Connecticut River Valley in and wild oats usually occur in transitions ferns, Christmas fern and wood ferns, that Massachusetts. They are associated with to surrounding forest types. RMF lack. Oak - Hickory Forests and outcrops of circumneutral rock and slopes Dry, Rich Oak Forests/Woodlands lack below them that have more nutrients than abundant sugar maple, basswood, and are available in the surrounding forest.
  • Discoloration of Norway Spruce and Scots Pine Timber During Drying

    Discoloration of Norway Spruce and Scots Pine Timber During Drying

    Discoloration of Norway spruce and Scots pine timber during drying V. Tarvainen VTT Building and Transport, Puumiehenk. 2A Espoo, P.O.Box 1806 FIN-02044 VTT, Finland. Internet: [email protected] P. Saranpää Metla - The Finnish Forest Research Institute, J. Repola P.O. Box 18, FIN-01301 VANTAA, Finland Internet: [email protected], [email protected] ABSTRACT The effect of growth site, felling time (winter, spring and autumn) and wet storage on the discoloration of spruce (Picea abies (L.) Karst.) and pine (Pinus sylvestris L.) dried at different temperatures was studied. Two dominant trees were selected at each cutting season from a fertile and a poor site. Some of the logs felled in May were stored under sprinklers for 6 weeks. The butt logs were cant-sawn with a circular saw. The temperatures for drying were 50, 70, 90 and 110 °C. One group from autumn felling was dried in a vacuum kiln at 70 °C. Common drying schedules for 38-mm-thick pine boards were used. The surface colour (CIELAB L*, a*, b*) of boards was measured before and after drying with a spectrophotometer. Some of the boards were also measured after 0.5 mm and further 1.5 mm planing. Drying temperature was the most significant factor for discoloration of boards. The colour change of pine was quite similar to that of spruce except that there was a stronger darkening of pine heartwood compared to spruce at 90 °C. Discoloration in sapwood increased remarkably at temperatures above 70 °C. At 90 and 110 °C the lightness (L*) decreased significantly indicating darkening.
  • Variation of Basic Density and Brinell Hardness Within Mature Finnish Betula Pendula and B

    Variation of Basic Density and Brinell Hardness Within Mature Finnish Betula Pendula and B

    VARIATION OF BASIC DENSITY AND BRINELL HARDNESS WITHIN MATURE FINNISH BETULA PENDULA AND B. PUBESCENS STEMS Henrik Herujarvi Research Scientist Finnish Forest Research Institute Joensuu Research Centre P.O. Box 68 FIN-80101 Joensuu, Finland (Received November 200 1 ) ABSTRACT Thc objective of this study was to analyze the variation in basic density between different horizontal and vertical locations within mature Finnish Betula pendula and B. puhescens stems. In addition, the depen- dence of Brinell hardness in radial direction, which is of importance especially for the parquetry, veneer. and plywood industries, on the basic density was investigated. Furthermore, the sources of error in the Brinell hardness test according to EN 1534 were analyzed. Both basic density and Brinell hardness were measured from small. defect-free specimens. The average basic density of B. pendula and B. pubescerz.s were 5 12 kg/m3 and 478 kg/m3, respectively. Concerning both birch species, wood material near the pith was clearly less dense than near the surface of the stem. The average Brinell hardness of B. pendula spec- irnens was 23.4 MPa, and that of B. pubescens specimens was 20.5 MPa. Brinell hardness was found to be positively correlated with basic density. Therefore, the assumption that Brinell hardness varies within a birch stem similarly to basic density is confirmed. The test method according to the EN 1534 standard was found to hc precise enough hut unnecessarily laborious for hardness tests. Finally, an alternative method is s~~ggestedfor determining Brinell hardness on an industrial scale. Kryw,orti.c: Basic density. Brinell hardness, Betula pendul(~,Beruln puhescens, furnishing, parquet, veneer, plywood.
  • Chestnut Oak Botanical/Latin Name Quercus Montana

    Chestnut Oak Botanical/Latin Name Quercus Montana

    Chestnut Oak Botanical/Latin name Quercus Montana Chestnut Oak owes its name to its leaves, 4”-6” long, looking like those of the American Chestnut. It is a species of oak in the white oak group native to eastern U.S. Predominantly a ridge-top tree in hardwood forests. Also called Mountain Oak or Rock Oak because it grows in dry rocky habitats, sometimes even around large rocks. As a consequence of its dry habitat and harsh ridge-top exposure, it is not usually large, 59’–72’ tall; specimens growing in better conditions however can become large, up to 141’. It is a long-lived tree, with high-quality timber when well-formed. The heavy, durable, close-grained wood is used for fence posts, fuel, railroad ties and tannin. Saplings are easier to transplant than many other oaks because the taproot of the seedling disintegrates as the tree grows, and the remaining roots form a dense mat about three feet deep. It is monoecious, having pollen-bearing catkins in mid-spring that fertilize the inconspicuous female flowers on the same tree. It reproduces from seed as well as stump sprouts. The 1”-1-1/2” long acorns mature in one growing season, are among the largest of native American oaks and are a valuable wildlife food. Acorns are produced when a tree grown from seed is about 20 years of age, but sprouts from cut stumps can produce acorns in as little as three years after cutting. Extensive confusion between the chestnut oak (Q. montana) and the swamp chestnut oak (Quercus michauxii) has historically occurred.
  • Douglasfirdouglasfirfacts About

    Douglasfirdouglasfirfacts About

    DouglasFirDouglasFirfacts about Douglas Fir, a distinctive North American tree growing in all states from the Rocky Mountains to the Pacific Ocean, is probably used for more Beams and Stringers as well as Posts and Timber grades include lumber and lumber product purposes than any other individual species Select Structural, Construction, Standard and Utility. Light Framing grown on the American Continent. lumber is divided into Select Structural, Construction, Standard, The total Douglas Fir sawtimber stand in the Western Woods Region is Utility, Economy, 1500f Industrial, and 1200f Industrial grades, estimated at 609 billion board feet. Douglas Fir lumber is used for all giving the user a broad selection from which to choose. purposes to which lumber is normally put - for residential building, light Factory lumber is graded according to the rules for all species, and and heavy construction, woodwork, boxes and crates, industrial usage, separated into Factory Select, No. 1 Shop, No. 2 Shop and No. 3 poles, ties and in the manufacture of specialty products. It is one of the Shop in 5/4 and thicker and into Inch Factory Select and No. 1 and volume woods of the Western Woods Region. No. 2 Shop in 4/4. Distribution Botanical Classification In the Western Douglas Fir is manufactured by a large number of Western Woods Douglas Fir was discovered and classified by botanist David Douglas in Woods Region, Region sawmills and is widely distributed throughout the United 1826. Botanically, it is not a true fir but a species distinct in itself known Douglas Fir trees States and foreign countries. Obtainable in straight car lots, it can as Pseudotsuga taxifolia.