ASTM D2395-17(2022)
(Test Method)Standard Test Methods for Density and Specific Gravity (Relative Density) of Wood and Wood-Based Materials
Standard Test Methods for Density and Specific Gravity (Relative Density) of Wood and Wood-Based Materials
SIGNIFICANCE AND USE
5.1 Density and specific gravity are cornerstone terms that help define many useful properties of wood and wood-based materials. These terms designate concepts that have distinct definitions though they relate to the same characteristic (mass in a unit volume). Generally, in the US and Canada, density of wood is measured in terms of specific gravity, or relative density. In the wood-based composites industry and internationally the term density is often preferred.
5.2 The basic density and basic specific gravity of wood are used in the forestry industry for calculating the oven-dry weight of wood fiber contained in a known wood volume of various wood species. Thus, it serves as an indicator of the amount of wood pulp that could be produced, the workability of the material or its shipping weight. This information is referenced in various resources, including Wood Handbook.5 Note that specific gravity varies within a tree, between trees, and between species. Since the specific gravity of wood cell wall substance is practically constant for all species (approximately 1.53), it is apparent that individual specific gravity value is indicative of the amount of wood cell wall substance present. It affords a rapid and valuable test method for selection of wood for specific uses. In US and Canadian building codes, the oven-dry specific gravity is correlated to various strength characteristics of wood products (for example, compression perpendicular to grain, shear strength and fastener holding capacity).
5.3 It is often desirable to know the density or specific gravity of a living tree, a structural member already in place, a log cross section, a segment of a research element, or the earlywood or latewood layer. Therefore, it is possible that specimens will be large or small, regular or irregular in shape, and at a variety of moisture contents. These test methods give procedures that include all of these variables and provides for calculation of density and specific gr...
SCOPE
1.1 These test methods cover the determination of the density and specific gravity (relative density) of wood and wood-based materials to generally desired degrees of accuracy and for specimens of different sizes, shapes, and moisture content conditions. The test method title is indicative of the procedures used or the specific area of use.
Section
Test Method A—Volume by Measurement
8
Test Method B—Volume by Water Immersion
9
Test Method C—Flotation Tube
10
Test Method D—Forstner Bit
11
Test Method E—Increment Core
12
Test Method F—Chips
13
Test Method G—Full-Size Members
14
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
Relations
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:D2395 −17 (Reapproved 2022)
Standard Test Methods for
Density and Specific Gravity (Relative Density) of Wood and
Wood-Based Materials
This standard is issued under the fixed designation D2395; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope D4442Test Methods for Direct Moisture Content Measure-
ment of Wood and Wood-Based Materials
1.1 These test methods cover the determination of the
D5456Specification for Evaluation of Structural Composite
density and specific gravity (relative density) of wood and
Lumber Products
wood-based materials to generally desired degrees of accuracy
D7438Practice for Field Calibration and Application of
and for specimens of different sizes, shapes, and moisture
Hand-Held Moisture Meters
content conditions. The test method title is indicative of the
E1547Terminology Relating to Industrial and Specialty
procedures used or the specific area of use.
Chemicals
Section
2.2 Other Standards:
TestMethodA—VolumebyMeasurement 8
TestMethodB—VolumebyWaterImmersion 9
CAN/CSAO86Engineering Design in Wood
TestMethodC—FlotationTube 10
ANSI/AWCNational Design Specification for Wood Con-
TestMethodD—ForstnerBit 11
struction
TestMethodE—IncrementCore 12
TestMethodF—Chips 13
Test Method G—Full-Size Members 14 3. Terminology
1.2 This standard does not purport to address all of the
3.1 Definitions:
safety concerns, if any, associated with its use. It is the
3.1.1 For definitions of terms used in this standard, refer to
responsibility of the user of this standard to establish appro-
Terminology D9.
priate safety, health, and environmental practices and deter-
3.2 Definitions of Terms Specific to This Standard:
mine the applicability of regulatory limitations prior to use.
3 3 3
3.2.1 density, ρ [kg/m , g/cm or lb/ft ],n—mass of a unit
1.3 This international standard was developed in accor-
volume of a specimen at specified moisture content.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
NOTE 1—The moisture content is specified for both mass and volume.
For further discussion, see Appendix X3.
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical 3.2.1.1 density at moisture content M—density based on the
Barriers to Trade (TBT) Committee. mass of a specimen including moisture and its volume at the
same moisture content.
2. Referenced Documents
NOTE2—Themassandvolumeat12%moisturecontentarefrequently
used.
2.1 ASTM Standards:
D9Terminology Relating to Wood and Wood-Based Prod-
3.2.1.2 density, basic or conventional, ρ —density based on
b
ucts
the oven-dry mass of a specimen and its green volume.
D2555PracticeforEstablishingClearWoodStrengthValues
3.2.1.3 density, oven-dry or in the absolute dry condition,
ρ —density based on the oven-dry mass of a specimen and its
oven-dry volume.
These test methods are under the jurisdiction of ASTM Committee D07 on
3.2.2 green volume, n—volume of wood specimen before
Wood and are the direct responsibility of Subcommittee D07.01 on Fundamental
any shrinkage occurs due to drying to moisture content below
Test Methods and Properties.
the fiber saturation point (about 30%).
Current edition approved Aug. 1, 2022. Published September 2022. Originally
approved in 1965. Last previous edition approved in 2017 as D2395–17. DOI:
10.1520/D2395-17R22.
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Available from CSAGroup, 5060 Spectrum Way, Mississauga, ON L4W 5N6,
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Canada, http://www.csa.ca.
Standards volume information, refer to the standard’s Document Summary page on Available fromAmericanWood Council (AWC) 222 Catoctin Circle, SE, Suite
the ASTM website. 201 Leesburg, VA 20175, www.awc.org.
Copyright ©ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA19428-2959. United States
D2395−17 (2022)
NOTE 3—Green volume may also be obtained by water soaking of
5.2 The basic densityand basic specific gravityofwoodare
partially dry wood specimens until they reach fully swollen condition
used in the forestry industry for calculating the oven-dry
above the fiber saturation point (for example, see 13.2.3.1). The fiber
weight of wood fiber contained in a known wood volume of
saturation point of wood averages approximately 30% moisture content,
various wood species. Thus, it serves as an indicator of the
but in individual species and individual pieces of wood it can vary by
amount of wood pulp that could be produced, the workability
several percentage points from that value. For further discussion, see
Appendix X3.
of the material or its shipping weight. This information is
referenced in various resources, including Wood Handbook.
3.2.3 moisture content, M [%]—amount of water contained
Note that specific gravity varies within a tree, between trees,
in a specimen, expressed as a percentage of its oven-dry mass.
and between species. Since the specific gravity of wood cell
3.2.4 specific gravity (relative density), S, n—ratio of the
wall substance is practically constant for all species (approxi-
oven-dry mass of a specimen to the mass of a volume of water
mately 1.53), it is apparent that individual specific gravity
equal to the volume of the specimen at a specified moisture
value is indicative of the amount of wood cell wall substance
content.
present.Itaffordsarapidandvaluabletestmethodforselection
NOTE 4—The volume may be that in the oven-dry, partially dry, or
of wood for specific uses. In US and Canadian building codes,
green(fullyswollen)condition.Furtherinthisstandard,thetermsspecific
the oven-dry specific gravity is correlated to various strength
gravity and relative density are used interchangeably. For further
characteristics of wood products (for example, compression
discussion, see Appendix X3.
perpendicular to grain, shear strength and fastener holding
3.2.4.1 specific gravity at moisture content M, n—specific
capacity).
gravity based on the oven-dry mass of a specimen and its
5.3 It is often desirable to know the density or specific
volume at a specified moisture content between the oven-dry
gravity of a living tree, a structural member already in place, a
condition and the fiber saturation point.
log cross section, a segment of a research element, or the
NOTE 5—The volume at 12% moisture content is frequently used.
earlywood or latewood layer. Therefore, it is possible that
specimens will be large or small, regular or irregular in shape,
3.2.4.2 specific gravity, basic (or green), S,n—specific
b
and at a variety of moisture contents. These test methods give
gravitybasedontheoven-drymassofaspecimenanditsgreen
procedures that include all of these variables and provides for
volume.
calculation of density and specific gravity values to degrees of
3.2.4.3 specific gravity, oven-dry or on oven-dry basis, S ,
precision generally needed.
n—specific gravity based on the oven-dry mass of a specimen
5.4 In the wood-based composites industry, the product
and its oven-dry volume.
density or specific gravity also provides an important indicator
of potential product attributes. For wood-based materials, the
4. Summary of Test Methods
same test methods are used; however, the measurements
4.1 Theprecisionoftestresultsobtainedonarepresentative
typically combine the mass from the wood substance with any
specimen depends upon the precision of the measurements
resin, wax, or other solid additives present in the material.
made. Test Method A is used for precise measurements when
Thesepropertiesarenottobeconfusedwithequivalentspecific
thespecimensarecarefullypreparedandregularinshape.Test
gravity of structural composite lumber used to characterize its
Method B is used for precise measurements if the specimens
fastener-holding capacity determined in accordance with
are irregularly shaped and if due care is taken to prevent
Specification D5456.
sorptionofwater.TestMethodCisanapproximatetestmethod
thatispermittedforuseaspartofaproductionprocedureorin
6. Test Specimens
other situations where less precision is acceptable. Test Meth-
6.1 The test specimens shall be fully representative of the
ods D and E are especially adapted to density or specific
materialfromwhichtheyaretaken.Thespecimensizeshallbe
gravity measurements of living trees or of in-place elements,
such that accurate measurements of mass and volume are easy
and the precision of the result is dependent upon the care used
toattain.Whereotherstandardsspecifythelocationandsizeof
in obtaining the specimen. Test Method F is a specific
test specimens, these requirements shall be carefully followed.
procedureforwoodchips.TestMethodGprovidesaprocedure
With the exception of Test Method G, the specimens shall be
to estimate the overall density or specific gravity of a full-size
carefully cut from the larger element to ensure clean-cut
rectangularmemberthatincludestypicalgrowthandmanufac-
surfaces.All loose fibers shall be carefully removed before the
turing characteristics.
specimenisweighedandmeasured.Thespecimenshallbefree
fromknots,andifpitchorotherinfiltratesarepresent,thisshall
5. Significance and Use
be noted in the report or they shall be extracted before taking
measurements and weighing. The specimens for Test Method
5.1 Density and specific gravity are cornerstone terms that
Gshallbefull-sizerectangularmembers.WhenTestMethodG
help define many useful properties of wood and wood-based
is used with solid wood lumber, the specimens shall be
materials. These terms designate concepts that have distinct
permitted to include knots, wane, edge easing, pitch, or other
definitions though they relate to the same characteristic (mass
typical growth or manufacturing characteristics.
in a unit volume). Generally, in the US and Canada, density of
wood is measured in terms of specific gravity,or relative
density. In the wood-based composites industry and interna-
Forest Products Laboratory General Technical Report FPL-GTR-190, Wood
tionally the term density is often preferred. Handbook: Wood as Engineering Material, Forest Products Society, 2010.
D2395−17 (2022)
6.2 Measurements—The dimensions of test specimens shall 8.2.2 Initial Mass, (m )—Determine the initial mass of the
M
be measured to a precision of 60.3% or less, and the mass specimen at the time of test in accordance with 6.2.
shall be determined to a precision of 60.2% or less. Where
8.2.3 Oven-dry Mass (m )—Oven-drymassofthespecimen
drying of specimens is required, this shall be done in a forced shall be determined by drying to practical equilibrium in
convection oven that can be maintained at 103°C 6 2°C
accordance with 6.2 or by calculation in accordance with
throughout the drying chamber for the time required to dry the 15.1.2 if a moisture meter is used (7.1.2).
specimen to reach practical equilibrium. The oven shall be
8.2.4 Moisture Content—Determine the moisture content
vented to allow the evaporated moisture to escape. (M) of the specimen in accordance with 7.1.
NOTE6—Formostspecimensofwoodandstructuralcompositelumber
1in.(25mm)inlengthparalleltograin,dryingfor24hinanovenhaving
9. Test Method B—Volume by Water Immersion
good air circulation and exchange will be sufficient to reach practical
equilibrium (no more than 0.2% mass change over 8 h period of drying). 9.1 Applicability:
For other wood-based materials, the drying time should be established by
9.1.1 This procedure is particularly adaptable to clear wood
test. For further discussion, see Appendix X3.
specimens of irregular shape or having a rough surface.
7. Moisture Content
NOTE 8—Limitations on specimen size are based primarily on size of
immersion tanks available. In small size specimens, less than 1 cm in
7.1 The moisture content (M) of the specimens shall be
volume, air bubbles adhering to the specimen surface can result in
measured to identify the basis on which the density or specific
considerable error in volume measurement and thus in the computed
gravity is determined. The method of determination of the
density or specific gravity value. Freshly cut green wood will not absorb
moisture content depends on the size of the specimen and the appreciable quantities of water during the brief immersion period. If any
drying has taken place, the surface of the specimen needs to be sealed
purpose of the test.
before immersion in water or else the volumetric displacement of the
7.1.1 Oven Drying—The moisture content shall be deter-
specimen will be in error in an amount equal to the volume of water
mined using the oven-dry procedures of Test Method D4442.
absorbed by the wood.
With small specimens of convenient size that can be oven-
9.2 Procedures:
dried within a reasonable timeframe, the entire piece shall be
9.2.1 Initial Mass (m )—Determine the initial mass of the
M
used for the moisture content determination. With larger
specimen at time of test in accordance with 6.2.
specimens that cannot be conveniently oven-dried, at least one
9.2.2 Volume—Determine the volume of the specimen by
representativesegmentshallbecutfromthefull-sizespecimen
measuringthevolumeorthemassofthewaterdisplacedbythe
for the moisture content determination. In this case, the
specimenusingoneofthefollowingmodes.Themassofwater
moisture content specimens shall be as large as can be
in grams is numerically equal to its volume in cubic centime-
practically dried in a reasonable timeframe and cut away from
ters. Unless the volume is determined on a specimen of green
the member ends, wherever possible.
wood, the surfaces of the specimen shall be adequately sealed
7.1.2 Moisture Meter—Where a large solid wood specimen
(see 9.2.2.5).
cannot be cut to secure a moisture content segment for oven
9.2.2.1 Mode I—Place the specimen in a tank of known
drying, an approximate moisture content shall be permitted to
volume and add sufficient water to fill the tank with the
be obtained through the use of a moisture meter in accordance
specimen being fully submerged. Then remove the specimen
withPracticeD7438.Themeterreadingsshallbecorrectedfor
and determine the volume of water remaining. The tank
temperature and species. The use of moisture meters shall not
volume less th
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