ASTM B215-20

Standard Practices for Sampling Metal Powders

SIGNIFICANCE AND USE
4.1 Specifications and test methods for metal powders and metal powder products require the sampling, testing, and performance evaluation of small samples taken from large quantities of powder. The sampling procedure is equally as important as the testing and evaluation; the sampling methods used must include every precaution to ensure that the samples obtained will show the true nature and condition of the large powder quantity that they represent.  
4.2 The primary objective of any sampling procedure is to obtain a small quantity of material that is truly representative of the larger amount from which it is taken, a condition that is readily comprehended but difficult to define, quantify, and prove. Certain criteria are desirable to meet this condition:3  
4.2.1 Every sampling increment should have a non-zero probability of being selected.  
4.2.2 All increments should have an equal probability of being selected.  
4.2.3 The sampling procedure should not alter the material (for example, by changing the particle size or chemical composition).  
4.3 Sampling a moving powder helps to satisfy these criteria; therefore, Practice 1A should be used whenever possible to obtain the composite sample. Similarly, Practice 2 should be used to obtain the test portions; use of a spinning riffler is preferred when possible and practicable.  
4.4 Although not always meeting all the criteria of 4.2.1 – 4.2.3, the other sampling practices described in this standard are based on time-proven experience in the PM industry in sampling granular metal powders. These practices have been shown to produce samples that give reliable and representative evaluation data.  
4.5 Since many tests are performed using very small amounts of powder meant to represent much larger quantities, it is most important that the test portions be obtained in a standardized manner. The practices described here take into account the possibility of segregation of the metal powder during and after filling of ...
SCOPE
1.1 These practices cover sampling methods used to collect a small quantity of metal powder that is as representative of the entire starting material as possible, and detail the procedures that are recommended for reducing this quantity into smaller test portions on which chemical, physical, and mechanical property data may be determined.  
1.2 Several sampling practices are described, depending on their applicability to the conditions of storage and transport of the sampled powders:  
1.2.1 Practice 1A (Described in Section 6)—Applicable to sampling moving powders, as when being transferred from one container to another or to a process stream; or when falling from a conveyor; or in a moving process stream. This is the preferred practice for obtaining the several increments that are combined to form the gross sample.  
1.2.2 Practice 1B (Described in Section 7)—Applicable to sampling powders that have already been packaged for transport, as in a bag or drum. A hollow tubular slot sampler is the recommended way to sample these packaged powders to obtain the increments (7.1.1). Alternatively, when other methods are not possible or available, a procedure specified here (7.1.2) may be used to randomly scoop samples from the powder, using a scoop of specified material and configuration.  
1.2.3 Practice 2 (Described in Section 8)—Applicable to obtaining test portions from the composite sample. For larger quantities of powder, a chute splitter is generally used, while a spinning riffler is used for smaller quantities.  
1.3 These practices apply to particulate materials or mixtures of particulates with particle sizes generally less than one millimetre and include mixtures containing lubricant, with or without other non-metallic additives, that are ready for compacting.  
1.4 These practices do not cover the sampling of flake powders or pastes. For procedures on the sampling and testing of flake metal powders and pastes, ...

General Information

• Status: Published
• Publication Date: 31-Oct-2020
• ICS: 77.160 - Powder metallurgy
• Technical Committee: B09 - Metal Powders and Metal Powder Products
• Drafting Committee: B09.02 - Base Metal Powders

Relations

• Refers: ASTM D480-88(2020) - Standard Test Methods for Sampling and Testing of Flaked Aluminum Powders and Pastes
• Effective Date: 01-Jun-2020
• Refers: ASTM B243-18 - Standard Terminology of Powder Metallurgy
• Effective Date: 01-Oct-2018
• Refers: ASTM B243-16 - Standard Terminology of Powder Metallurgy
• Effective Date: 01-Jul-2016
• Refers: ASTM D480-88(2014) - Standard Test Methods for Sampling and Testing of Flaked Aluminum Powders and Pastes
• Effective Date: 01-Dec-2014
• Refers: ASTM B243-13 - Standard Terminology of Powder Metallurgy
• Effective Date: 01-Nov-2013
• Refers: ASTM B243-12 - Standard Terminology of Powder Metallurgy
• Effective Date: 15-Jul-2012
• Refers: ASTM B243-11 - Standard Terminology of Powder Metallurgy
• Effective Date: 15-Nov-2011
• Refers: ASTM B243-10 - Standard Terminology of Powder Metallurgy
• Effective Date: 15-Jan-2010
• Refers: ASTM B243-09a - Standard Terminology of Powder Metallurgy
• Effective Date: 15-Dec-2009
• Refers: ASTM B243-09 - Standard Terminology of Powder Metallurgy
• Effective Date: 01-Jan-2009
• Refers: ASTM D480-88(2008) - Standard Test Methods for Sampling and Testing of Flaked Aluminum Powders and Pastes
• Effective Date: 01-Jul-2008
• Refers: ASTM B243-08a - Standard Terminology of Powder Metallurgy
• Effective Date: 15-Mar-2008
• Refers: ASTM B243-08 - Standard Terminology of Powder Metallurgy
• Effective Date: 01-Feb-2008
• Refers: ASTM B243-06 - Standard Terminology of Powder Metallurgy
• Effective Date: 01-Nov-2006
• Refers: ASTM B243-05b - Standard Terminology of Powder Metallurgy
• Effective Date: 01-Oct-2005

Overview

ASTM B215-20: Standard Practices for Sampling Metal Powders sets out accepted methods for the representative sampling of metal powders from bulk quantities, crucial for accurate testing and evaluation. Developed by ASTM International, this standard is widely recognized and supports quality control, production assurance, and regulatory compliance in the powder metallurgy (PM) industry. By outlining procedures to collect small, representative samples from large lots or batches of metal powders, ASTM B215-20 helps maintain consistency and integrity throughout various stages of material testing, including chemical, physical, and mechanical property determination.

Key Topics

• Sampling Objectives
  Ensuring that test samples are truly representative of their source material is central to ASTM B215-20. Proper sampling minimizes risk of bias and provides reliable data for decision-making.

• Sampling Methods
  Depending on whether the metal powder is moving (during transfer or processing) or stationary (packaged in bags, drums, etc.), the standard describes several practices:

  • Practice 1A: Preferred for sampling powders in motion, such as during transfer or within process streams.
  • Practice 1B: For sampling stationary powders already packaged, using devices like a slot or tube sampler, or alternatively, specialized scoop sampling methods.
  • Practice 2: Methods for dividing the composite sample into smaller, testable portions-generally using a chute splitter for large samples or a spinning riffler for small-scale division.

• Sampling Devices
  The standard covers equipment such as rectangular receptacles for moving powders, hollow-tube slot samplers, non-magnetic stainless steel scoops, chute splitters, and spinning rifflers. Proper device selection impacts the integrity and representativeness of the sample.

• Sample Blending and Division
  ASTM B215-20 emphasizes blending increments into a composite sample and then dividing into test portions in a standardized way, considering the dangers of material segregation and potential sample alteration.

Applications

ASTM B215-20 is essential across a range of powder metallurgy and manufacturing processes, providing value in:

• Quality Control and Inspection
  By standardizing how representative metal powder samples are taken, manufacturers can accurately assess chemical composition, particle size, and physical or mechanical properties, ensuring materials meet product specifications.
• Material Evaluation and Product Development
  Laboratories and R&D departments use ASTM B215-20 methods to produce reliable data for new powder metallurgy materials and products.
• Compliance and Certification
  Many regulatory bodies and procurement contracts reference ASTM B215-20 to ensure consistent sampling and evaluation methods for bulk powdered metals.
• Process Optimization
  Following this standard allows process engineers to monitor batch uniformity, minimize material waste, and optimize processing parameters in production lines.

Related Standards

• ASTM B243: Terminology of Powder Metallurgy
  Provides definitions and terms related to PM, essential for understanding ASTM B215-20.

• ASTM D480: Test Methods for Sampling and Testing of Flaked Aluminum Powders and Pastes
  For sampling flake powders and pastes, referenced for materials outside the scope of ASTM B215-20.

• Other Relevant Standards

  • ISO powder metallurgy sampling methods (as adopted in various countries)
  • Industry-specific quality management systems referencing ASTM B215-20

Keywords: metal powder sampling, ASTM B215, powder metallurgy, representative sample, quality control, chute splitter, spinning riffler, material testing, powder processing, standards compliance.

By following the practices outlined in ASTM B215-20, organizations can support reliable testing, ensure regulatory compliance, and maintain high standards within the metal powder supply chain.

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: B215 − 20
Standard Practices for
Sampling Metal Powders
This standard is issued under the fixed designation B215; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number 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* 1.5 Units—The values stated in inch-pound units are to be
regarded as standard. The values given in parentheses are
1.1 These practices cover sampling methods used to collect
mathematical conversions to SI units that are provided for
asmallquantityofmetalpowderthatisasrepresentativeofthe
information only and are not considered standard.
entire starting material as possible, and detail the procedures
that are recommended for reducing this quantity into smaller 1.6 This standard does not purport to address all of the
test portions on which chemical, physical, and mechanical safety concerns, if any, associated with its use. It is the
property data may be determined. responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
1.2 Several sampling practices are described, depending on
mine the applicability of regulatory limitations prior to use.
their applicability to the conditions of storage and transport of
1.7 This international standard was developed in accor-
the sampled powders:
dance with internationally recognized principles on standard-
1.2.1 Practice 1A (Described in Section 6)—Applicable to
ization established in the Decision on Principles for the
samplingmovingpowders,aswhenbeingtransferredfromone
Development of International Standards, Guides and Recom-
container to another or to a process stream; or when falling
mendations issued by the World Trade Organization Technical
from a conveyor; or in a moving process stream. This is the
Barriers to Trade (TBT) Committee.
preferred practice for obtaining the several increments that are
combined to form the gross sample.
2. Referenced Documents
1.2.2 Practice 1B (Described in Section 7)—Applicable to
sampling powders that have already been packaged for
2.1 ASTM Standards:
transport, as in a bag or drum.Ahollow tubular slot sampler is
B243 Terminology of Powder Metallurgy
the recommended way to sample these packaged powders to
D480 Test Methods for Sampling and Testing of Flaked
obtain the increments (7.1.1). Alternatively, when other meth-
Aluminum Powders and Pastes
ods are not possible or available, a procedure specified here
(7.1.2) may be used to randomly scoop samples from the
3. Terminology
powder, using a scoop of specified material and configuration.
3.1 Definitions—Definitions of powder metallurgy terms
1.2.3 Practice 2 (Described in Section 8)—Applicable to
can be found in Terminology B243. Additional descriptive
obtaining test portions from the composite sample. For larger
information is available in the Related Materials section of Vol
quantities of powder, a chute splitter is generally used, while a
02.05 of the Annual Book of ASTM Standards.
spinning riffler is used for smaller quantities.
3.2 Definitions of Terms Specific to This Standard:
1.3 These practices apply to particulate materials or mix-
3.2.1 See Fig. 1 for the terms hereinafter defined.
tures of particulates with particle sizes generally less than one
3.2.2 composite sample, n—blended entire gross sample.
millimetre and include mixtures containing lubricant, with or
without other non-metallic additives, that are ready for com-
3.2.3 increment, n—quantity of powder obtained by a sam-
pacting.
pling device at one time from a larger quantity of powder.
1.4 These practices do not cover the sampling of flake
3.2.4 gross sample, n—totalquantityofpowderadequatefor
powders or pastes. For procedures on the sampling and testing
the intended purpose(s), consisting of all the increments
of flake metal powders and pastes, refer toTest Methods D480.
combined.
These practices are under the jurisdiction of ASTM Committee B09 on Metal
Powders and Metal Powder Products and are the direct responsibility of Subcom-
mittee B09.02 on Base Metal Powders. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2020. Published November 2020. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1946. Last previous edition approved in 2015 as B215 – 15. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/B0215-20. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B215 − 20
4.2.3 The sampling procedure should not alter the material
(for example, by changing the particle size or chemical
composition).
4.3 Sampling a moving powder helps to satisfy these crite-
ria; therefore, Practice 1Ashould be used whenever possible to
obtain the composite sample. Similarly, Practice 2 should be
used to obtain the test portions; use of a spinning riffler is
preferred when possible and practicable.
4.4 Although not always meeting all the criteria of 4.2.1 –
4.2.3, the other sampling practices described in this standard
are based on time-proven experience in the PM industry in
sampling granular metal powders. These practices have been
shown to produce samples that give reliable and representative
evaluation data.
4.5 Since many tests are performed using very small
amounts of powder meant to represent much larger quantities,
it is most important that the test portions be obtained in a
standardized manner. The practices described here take into
account the possibility of segregation of the metal powder
during and after filling of containers.
4.6 Sample quantities of metal powder are used for chemi-
cal analysis and to determine the physical characteristics of the
powder. These data are used for production control and quality
inspection of finished lots.
4.7 Green compacts produced from powder samples are
used to evaluate the compactability properties of metal
powders, information that is important to the use of these
powders in the manufacture of PM bearings and structural
parts.
FIG. 1 Scheme of Sampling
4.8 Test specimens produced from metal powder samples
are compacted and sintered and used to measure physical and
3.2.5 test portion, n—quantity of powder (generally taken mechanicalpropertiesofsolidPMmaterials.Thedataobtained
from the composite sample) on which the test is performed, or are included in PM material specifications to assist with
from which a test piece is produced. material selection for PM applications.
4.9 Solid PM articles—structural parts, bearings, etc.—are
4. Significance and Use
produced from metal powder samples to evaluate powder
4.1 Specifications and test methods for metal powders and
performance in the manufacturing and end use of such articles.
metal powder products require the sampling, testing, and
performance evaluation of small samples taken from large
5. Apparatus
quantities of powder. The sampling procedure is equally as
5.1 Rectangular Receptacle, capable of being moved com-
important as the testing and evaluation; the sampling methods
pletely across a stream of flowing powder at a constant speed
used must include every precaution to ensure that the samples
and having a length and width greater than the stream of
obtained will show the true nature and condition of the large
powder. It must be large enough so that no overflow of powder
powder quantity that they represent.
occurs when collecting the sample.
4.2 The primary objective of any sampling procedure is to
5.2 Small Blender, of sufficient capacity to blend the entire
obtainasmallquantityofmaterialthatistrulyrepresentativeof
gross sample, consisting of all the increments combined.
the larger amount from which it is taken, a condition that is
readily comprehended but difficult to define, quantify, and 5.3 Commercial Sampling Device—Many powder transfer
prove. Certain criteria are desirable to meet this condition: systems are closed for dust control, but there are commercial
4.2.1 Every sampling increment should have a non-zero devices available that can be inserted into a section of a pipe to
probability of being selected. collect powder increments while maintaining the flowing
4.2.2 All increments should have an equal probability of stream.
being selected.
5.4 Powder Sampler—A slot or tube sampler with an auger
pointthatcanbescrewedtothebottomofafilledcontainerand
is designed to collect powder at one (single-level) or more
Gy, P. M., Sampling of Heterogeneous and Dynamic Material Systems,
Elsevier: New York, NY, 1992. (multi-level) depths; see Fig. 2 and Fig. 3.
B215 − 20
FIG. 2 Multi-Level Slot Sampler with Auger Point
(Keystone Sampler)
FIG. 3 Single-Level Tube Sampler with Auger Point (Full View and Close-Up of Point) — Schematic
B215 − 20
5.5 Powder Scoop—A non-magnetic stainless steel scoop
withasharpedgeandhighsides,ofasizeandcapacitycapable
of obtaining the desired powder increment. See Fig. 4.
5.6 Chute Splitter, of sufficient size and capacity to split the
required amount of powder into two approximately-equal
portions. A lever-operated gate-type splitter is recommended,
so that the entire sample may be distributed evenly across the
width of the splitter and poured in one continuous motion. See
Fig. 5. Several different sizes of splitter may be necessary
throughoutthesamplingprocess,dependingonthesamplesize
at each step. The size of the chute openings should be at least
threetimesthelargestparticlesizetobesampled,andthechute
angle should be at least 45°. The smallest of the chute splitters
are often referred to as “micro splitters.”
5.7 Charging Pan or Hopper (Fig. 5)—Apan or hopper that
isthesamewidthasthechutesplitterandofasizesuchthatthe
sample to be split occupies at least 20 % of its volume.
5.8 Spinning Riffler, of sufficient size and capacity to split
the required amount of powder into at least eight
approximately-equal portions; see Fig. 6. Several different
sizes of riffler may be necessary throughout the sampling
process, depending on the sample size at each step. The
smallest of these are often referred to as “micro rifflers.”
PART 1—OBTAINING THE COMPOSITE SAMPLE
6. Practice 1A—Sampling a Moving Powder
6.1 The preferred method for sampling powders is always
when the powder is in motion, as, for example, when being
transferred from a blender or a storage tank, or falling from a
conveyor, or in a moving process stream (pipeline).
FIG. 5 Gate-Type Chute Splitter — Schematic
6.2 Equal powder increments should be taken at random
intervals over the life of the flow.
6.3 The number of increments that make up the gross
agreed-upon number of increments is obtained, taking the last
sample should be agreed upon between the parties concerned.
increment near the end of the flow.
6.4 Pass the rectangular receptacle at a constant speed
6.5 Alternatively, use a commercial sampling device to
completely through the stream of flowing powder, starting
collect the agreed-upon number of increments, starting imme-
immediately upon flow. Repeat at random intervals until the
diately upon flow, and taking the last increment near the end of
the flow.
6.6 The total amount from all increments shall be adequate
for the tests or evaluations to be performed.
NOTE 1—To investigate within-lot and sampling variability, individual
incrementsmaybetested,ratherthanbeingcombinedtoformacomposite
sample.
6.7 Combine the increments to form the gross sample.
6.8 Blend the gross sample in a small blender to form the
composite sample.
7. Practice 1B—Sampling a Stationary Powder
7.1 Although sa
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: B215 − 15 B215 − 20
Standard Practices for
Sampling Metal Powders
This standard is issued under the fixed designation B215; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number 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*
1.1 These practices cover sampling methods used to collect a small quantity of metal powder that is as representative of the entire
starting material as possible, and detailsdetail the procedures that are recommended for reducing this quantity into smaller test
portions on which chemical, physical, and mechanical property data may be determined.
1.2 Several sampling practices are described, depending on their applicability to the conditions of storage and transport of the
sampled powders:
1.2.1 Practice 1A (Described in Section 6)—Applicable to sampling moving powders, as when being transferred from one
container to another or to a process stream; or when falling from a conveyor; or in a moving process stream. This is the preferred
practice for obtaining the several increments that are combined to form the gross sample.
1.2.2 Practice 1B (Described in Section 7)—Applicable to sampling powders that have already been packaged for transport, as
in a bag or drum. A hollow tubular slot sampler is the recommended way to sample these packaged powders to obtain the
increments (7.1.1). Alternatively, when other methods are not possible or available, a procedure specified here (7.1.2) may be used
to randomly scoop samples from the powder, using a scoop of specified material and configuration.
1.2.3 Practice 2 (Described in Section 8)—Applicable to obtaining test portions from the composite sample. For larger quantities
of powder, a chute splitter is generally used, while a spinning riffler is used for smaller quantities.
1.3 These practices apply to particulate materials or mixtures of particulates with particle sizes generally less than one millimetre
and include mixtures containing lubricant, with or without other non-metallic additives, that are ready for compacting.
1.4 These practices do not cover the sampling of flake powders or pastes. For procedures on the sampling and testing of flake metal
powders and pastes, refer to Test Methods D480.
1.5 Units—The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
1.6 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
These practices are under the jurisdiction of ASTM Committee B09 on Metal Powders and Metal Powder Products and are the direct responsibility of Subcommittee
B09.02 on Base Metal Powders.
Current edition approved Oct. 1, 2015Nov. 1, 2020. Published October 2015November 2020. Originally approved in 1946. Last previous edition approved in 20102015
as B215 – 10.B215 – 15. DOI: 10.1520/B0215-15.10.1520/B0215-20.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B215 − 20
1.7 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.
2. Referenced Documents
2.1 ASTM Standards:
B243 Terminology of Powder Metallurgy
D480 Test Methods for Sampling and Testing of Flaked Aluminum Powders and Pastes
3. Terminology
3.1 Definitions—Definitions of powder metallurgy terms can be found in Terminology B243. Additional descriptive information
is available in the Related Materials section of Vol 02.05 of the Annual Book of ASTM Standards.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 See Fig. 1 for the terms hereinafter defined.
3.2.2 composite sample—sample, n—blended entire gross sample.
3.2.3 increment—increment, n—quantity of powder obtained by a sampling device at one time from a larger quantity of powder.
FIG. 1 Scheme of Sampling
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
B215 − 20
3.2.4 gross sample—sample, n—total quantity of powder adequate for the intended purpose(s), consisting of all the increments
combined.
3.2.5 test portion—portion, n—quantity of powder (generally taken from the composite sample) on which the test is performed,
or from which a test piece is produced.
4. Significance and Use
4.1 Specifications and test methods for metal powders and metal powder products require the sampling, testing, and performance
evaluation of small samples taken from large quantities of powder. The sampling procedure is equally as important as the testing
and evaluation; the sampling methods used must include every precaution to ensure that the samples obtained will show the true
nature and condition of the large powder quantity that they represent.
4.2 The primary objective of any sampling procedure is to obtain a small quantity of material that is truly representative of the
larger amount from which it is taken, a condition that is readily comprehended but difficult to define, quantify, and prove. Certain
criteria are desirable to meet this condition:
4.2.1 Every sampling increment should have a non-zero probability of being selected.
4.2.2 All increments should have an equal probability of being selected.
4.2.3 The sampling procedure should not alter the material (for example, by changing the particle size or chemical composition).
4.3 Sampling a moving powder helps to satisfy these criteria; therefore, Practice 1A should be used whenever possible to obtain
the composite sample. Similarly, Practice 2 should be used to obtain the test portions; use of a spinning riffler is preferred when
possible and practicable.
4.4 Although not always meeting all the criteria of 4.2.1 – 4.2.3, the other sampling practices described in this standard are based
on time-proven experience in the PM industry in sampling granular metal powders. These practices have been shown to produce
samples that give reliable and representative evaluation data.
4.5 Since many tests are performed using very small amounts of powder meant to represent much larger quantities, it is most
important that the test portions be obtained in a standardized manner. The practices described here take into account the possibility
of segregation of the metal powder during and after filling of containers.
4.6 Sample quantities of metal powder are used for chemical analysis and to determine the physical characteristics of the powder.
These data are used for production control and quality inspection of finished lots.
4.7 Green compacts produced from powder samples are used to evaluate the compactability properties of metal powders,
information that is important to the use of these powders in the manufacture of PM bearings and structural parts.
4.8 Test specimens produced from metal powder samples are compacted and sintered and used to measure physical and
mechanical properties of solid PM materials. The data obtained are included in PM material specifications to assist with material
selection for PM applications.
4.9 Solid PM articles—structural parts, bearings, etc.—are produced from metal powder samples to evaluate powder performance
in the manufacturing and end use of such articles.
Gy, PierreP. M., Sampling of Heterogeneous and Dynamic Material Systems, Elsevier: New York, NY, 1992.
B215 − 20
5. Apparatus
5.1 Rectangular Receptacle, capable of being moved completely across a stream of flowing powder at a constant speed and having
a length and width greater than the stream of powder. It must be large enough so that no overflow of powder occurs when collecting
the sample.
5.2 Small Blender—Blender, Ofof sufficient capacity to blend the entire gross sample, consisting of all the increments combined.
5.3 Commercial Sampling Device—Many powder transfer systems are closed for dust control, but there are commercial devices
available that can be inserted into a section of a pipe to collect powder increments while maintaining the flowing stream.
5.4 Powder Sampler—A slot or tube sampler with an auger point that can be screwed to the bottom of a filled container and is
designed to collect powder at one (single-level) or more (multi-level) depths,depths; see Fig. 2 and Fig. 3.
5.5 Powder Scoop—A non-magnetic stainless steel scoop with a sharp edge and high sides, of a size and capacity capable of
obtaining the desired powder increment. See Fig. 4.
5.6 Chute Splitter—Splitter, Ofof sufficient size and capacity to split the required amount of powder into two approximately-equal
portions, see portions. A lever-operated gate-type splitter is recommended, so that the entire sample may be distributed evenly
across the width of the splitter and poured in one continuous motion. See Fig. 5. Several different sizes of splitter may be necessary
throughout the sampling process, depending on the sample size at each step. The size of the chute openings should be at least three
times the largest particle size to be sampled, and the chute angle should be at least 45°. The smallest of the chute splitters are often
referred to as “micro splitters.”
5.7 Charging Pan—Pan or Hopper (Fig. 5)—A pan or hopper that is the same width as the chute splitter and large enough to
contain of a size such that the sample to be split.split occupies at least 20 % of its volume.
5.8 Spinning Riffler—Riffler, Ofof sufficient size and capacity to split the required amount of powder into at least eight
FIG. 2 Multi-Level Slot Sampler with Auger Point
(Keystone Sampler)
B215 − 20
FIG. 3 Single-Level Tube Sampler with Auger Point (Full View and Close-Up of Point) — Schematic
FIG. 4 Stainless Steel Scoop for Sampling Metal Powder
approximately-equal portions,portions; see Fig. 6. Several different sizes of riffler may be necessary throughout the sampling
process, depending on the sample size at each step. The smallest of these are often referred to as “micro rifflers.”
PART 1—OBTAINING THE COMPOSITE SAMPLE
6. Practice 1A—Sampling a Moving Powder
6.1 The preferred method for sampling powders is always when the powder is in motion, as, for example, when being transferred
from a blender or a storage tank, or falling from a conveyor, or in a moving process stream (pipeline).
B215 − 20
FIG. 5 Gate-Type Chute Splitter — Schematic
6.2 Equal powder increments should be taken at random intervals over the life of the flow.
6.3 The number of increments that make up the gross sample should be agreed upon between the parties concerned.
6.4 Pass the rectangular receptacle at a constant speed completely through the stream of flowing powder, starting immediately
upon flow. Repeat at random intervals until the agreed-upon number of increments is obtained, taking the last increment near the
end of the flow.
6.5 Alternatively, use a commercial sampling device to collect the agreed-upon number of increments, starting immediately upon
flow, and taking the last increment near the end of the flow.
6.6 The total amount from all increments shall be adequate for the tests or evaluations to be performed.
NOTE 1—To investigate within-lot and sampling variability, individual increments may be tested, rather than being combined to form a composite sample.
6.7 Combine the increments to form the gross sample.
6.8 Blend the gross sample in a small blender to form the composite sample.
7. Pract
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