ASTM B855-22

Standard Test Method for Volumetric Flow Rate of Metal Powders Using the Arnold Meter and Hall Flowmeter Funnel

SIGNIFICANCE AND USE
5.1 The volumetric flow rate is a measure of the flow characteristics of a metal powder. Measuring flow by volume compared with flow per unit mass eliminates the variable of the powder density and relates to the production practice of die filling by volume.  
5.2 The ability of a powder to flow and pack is a function of interparticle friction. As the surface area increases, the amount of friction in a powder mass also increases. Consequently, the friction between particles increases, giving less efficient flow and packing.  
5.3 Knowledge of the volumetric flow rate permits the part producer to estimate the number of parts that can be compacted per hour.  
5.4 This test may be part of the purchase agreement between metal powder producers and powder metallurgy (PM) part producers, or it can be an internal quality control test for any company using metal powders.
SCOPE
1.1 This test method covers a laboratory procedure for the quantitative determination of the flow rate of a specific volume of a free-flowing metal powder or lubricated powder mixture.  
1.2 Units—With the exception of the values for mass, volume, and density, for which the use of the gram and the cubic centimetre unit is long-standing industry practice, 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.  
1.3 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.  
1.4 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

• Status: Published
• Publication Date: 31-Aug-2022
• ICS: 17.120.01 - Measurement of fluid flow in general
• Technical Committee: B09 - Metal Powders and Metal Powder Products
• Drafting Committee: B09.02 - Base Metal Powders

Relations

• Refers: ASTM E456-13a(2022)e1 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 01-Apr-2022
• Refers: ASTM B213-20 - Standard Test Methods for Flow Rate of Metal Powders Using the Hall Flowmeter Funnel
• Effective Date: 01-Apr-2020
• Refers: ASTM B243-18 - Standard Terminology of Powder Metallurgy
• Effective Date: 01-Oct-2018
• Refers: ASTM E456-13A(2017)e1 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 01-Oct-2017
• Refers: ASTM E456-13A(2017)e3 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 01-Oct-2017
• Refers: ASTM B243-16 - Standard Terminology of Powder Metallurgy
• Effective Date: 01-Jul-2016
• Refers: ASTM E456-13a - Standard Terminology Relating to Quality and Statistics
• Effective Date: 15-Nov-2013
• Refers: ASTM E456-13ae1 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 15-Nov-2013
• Refers: ASTM E456-13ae2 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 15-Nov-2013
• Refers: ASTM E456-13ae3 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 15-Nov-2013
• Refers: ASTM B243-13 - Standard Terminology of Powder Metallurgy
• Effective Date: 01-Nov-2013
• Refers: ASTM E456-13 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 15-Aug-2013
• Refers: ASTM E691-13 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-May-2013
• Refers: ASTM B213-13 - Standard Test Methods for Flow Rate of Metal Powders Using the Hall Flowmeter Funnel
• Effective Date: 01-Apr-2013
• Refers: ASTM B243-12 - Standard Terminology of Powder Metallurgy
• Effective Date: 15-Jul-2012

Overview

ASTM B855-22 is the internationally recognized standard for determining the volumetric flow rate of free-flowing metal powders and lubricated powder mixtures using the Arnold Meter and Hall Flowmeter Funnel. Developed by ASTM Committee B09 on Metal Powders and Metal Powder Products, this test method provides a consistent laboratory procedure that measures how quickly a specified volume of powder can flow through a calibrated orifice. By assessing flow rate by volume, rather than by mass, the method eliminates variations due to powder density and aligns with volume-based production practices such as die filling in powder metallurgy.

Key Topics

• Volumetric Flow Rate Measurement: The standard focuses on determining the flow rate in seconds per 20 cubic centimetres (s/20 cm³), facilitating comparisons regardless of a powder's bulk density.
• Flow Characteristics of Metal Powders: Understanding interparticle friction and its effect on the powder's ability to flow and pack. Increased surface area leads to increased friction and less efficient flow.
• Quality Control and Production Planning: The flow data enable producers to estimate the number of parts that can be compacted per hour, improving planning and process efficiency.
• Sampling and Apparatus: Describes the preparation of precise powder samples using the Arnold Meter and the procedure for measuring flow through the Hall Flowmeter Funnel with calibrated timing devices.
• Lab Consistency: Instructions for repeatability and reproducibility help ensure reliable, comparable results within and across laboratories.

Applications

• Purchase Agreements: Manufacturers and buyers of metal powders often include this test as part of quality criteria in supply contracts.
• Powder Metallurgy (PM) Production: The method is widely used by PM part producers to control and optimize the die-filling process, which influences final product quality and consistency.
• Internal Quality Control: Any company using metal powders can utilize ASTM B855-22 for ongoing process monitoring, helping to prevent issues related to poor powder flow, such as uneven part density or production slowdowns.
• Research and Development: R&D teams rely on volumetric flow rate data to develop new formulations and optimize powder blends for best performance characteristics.

Related Standards

• ASTM B213: Test Methods for Flow Rate of Metal Powders Using the Hall Flowmeter Funnel, the core procedure referenced in B855-22.
• ASTM B215: Practices for Sampling Metal Powders, ensuring representative test samples.
• ASTM B243: Terminology of Powder Metallurgy, providing definitions key to understanding B855-22.
• ASTM B703: Test Method for Apparent Density of Metal Powders and Related Compounds Using the Arnold Meter.
• MPIF Standard 48: Method for Apparent Density of Metal Powders Using the Arnold Meter, an additional reference for industry practices.
• ASTM E456 / E691: Guidelines for statistical evaluation and interlaboratory studies.

Practical Value

ASTM B855-22 offers manufacturers, suppliers, and users of metal powders a robust method for quantifying powder flowability - a critical factor in powder handling, compaction, and part performance. This standard,

• Simplifies production planning by standardizing flow measurements
• Contributes to improved quality control for higher consistency and reliability
• Supports industry-wide communication through uniform terminology and procedures
• Helps ensure products meet required specifications and performance criteria

Keywords: ASTM B855-22, metal powder flow rate, volumetric flow rate, Arnold Meter, Hall Flowmeter Funnel, powder metallurgy, quality control, interparticle friction, powder handling, standard test method.

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: B855 − 22
Standard Test Method for
Volumetric Flow Rate of Metal Powders Using the Arnold
Meter and Hall Flowmeter Funnel
This standard is issued under the fixed designation B855; 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.
1. Scope* E691 Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
1.1 This test method covers a laboratory procedure for the
2.2 MPIF Standard
quantitative determination of the flow rate of a specific volume
MPIF Standard 48 Determination of Apparent Density of
of a free-flowing metal powder or lubricated powder mixture.
Metal Powders using the Arnold Meter
1.2 Units—With the exception of the values for mass,
volume, and density, for which the use of the gram and the
3. Terminology
cubic centimetre unit is long-standing industry practice, the
3.1 Definitions—Useful definitions of terms for metal pow-
values stated in inch-pound units are to be regarded as
ders and powder metallurgy used in this test method are found
standard. The values given in parentheses are mathematical
in Terminology B243. Additional descriptive PM information
conversions to SI units that are provided for information only
is available under “General Information on PM” on the B09
and are not considered standard.
web page.
1.3 This standard does not purport to address all of the
3.2 Definitions of Terms Specific to This Standard:
safety concerns, if any, associated with its use. It is the
3.2.1 volumetric flow rate, n—the relation between time and
responsibility of the user of this standard to establish appro-
volume of a free-flowing metal powder determined by mea-
priate safety, health, and environmental practices and deter-
suringthetimeforaspecificvolumetoflowthroughtheorifice
mine the applicability of regulatory limitations prior to use.
in a Hall Flowmeter Funnel and expressing the ratio in seconds
1.4 This international standard was developed in accor-
per 20 cubic centimetres (s/20 cm ).
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
4. Summary of Test Method
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
4.1 A20 cm test portion of powder is prepared from the lot
Barriers to Trade (TBT) Committee. to be tested following the procedures in Test Methods B215
and B703.
2. Referenced Documents
4.2 This 20 cm test portion is timed as it flows through the
2.1 ASTM Standards:
orifice in a Hall Flowmeter Funnel following the procedure in
B213 Test Methods for Flow Rate of Metal Powders Using
Test Method B213.
the Hall Flowmeter Funnel
4.3 The volumetric flow rate is calculated and reported in
B215 Practices for Sampling Metal Powders
seconds per 20 cubic centimetres (s/20 cm ).
B243 Terminology of Powder Metallurgy
B703 Test Method for Apparent Density of Metal Powders
5. Significance and Use
and Related Compounds Using the Arnold Meter
5.1 The volumetric flow rate is a measure of the flow
E456 Terminology Relating to Quality and Statistics
characteristics of a metal powder. Measuring flow by volume
comparedwithflowperunitmasseliminatesthevariableofthe
This test method is under the jurisdiction of ASTM Committee B09 on Metal powder density and relates to the production practice of die
Powders and Metal Powder Products and is the direct responsibility of Subcom-
filling by volume.
mittee B09.02 on Base Metal Powders.
Current edition approved Sept. 1, 2022. Published September 2022. Originally 5.2 The ability of a powder to flow and pack is a function of
approved in 1994. Last previous edition approved in 2017 as B855 – 17. DOI:
interparticle friction.As the surface area increases, the amount
10.1520/B0855-22.
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 Available from ASTM or Metal Powder Industries Federation, 105 College
the ASTM website. Road East, Princeton, NJ 08540 and initially reported in MPIF Standard 48
*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
B855 − 22
of friction in a powder mass also increases. Consequently, the 8.2 Using the scoop to carefully pour the sample into the
friction between particles increases, giving less efficient flow center of the funnel, determine the time required for the
and packing. powder to flow through the funnel following either of the
procedures described in Test Method B213.
5.3 Knowledge of the volumetric flow rate permits the part
producertoestimatethenumberofpartsthatcanbecompacted 8.3 Repeat 8.1 and 8.2 two more times, using a new 50 cm
per hour. test portion each time, and record each of the three flow time
determinations to the nearest 0.1 s.
5.4 Thistestmaybepartofthepurchaseagreementbetween
metal powder producers and powder metallurgy (PM) part
9. Calculation
producers, or it can be an internal quality control test for any
9.1 Averagethethreeflowtimes,multiplybytheCorrection
company using metal powders.
Factor forthefunnelbeingused,andcalculatetheArnold/Hall
6. Apparatus 3
Volumetric Flow Rate in s/20 cm units as follows:
6.1 Workbench—A level, vibration-free table or laboratory Arnold/Hall Flow Rate, s/20 cm =
workbench to support theArnold Meter and the Hall Flowme-
Avg. flow time 3 Funnel Correction Factor
(1)
ter apparatus.
20 cm
6.2 Arnold Meter —The steel die block and powder deliv-
10. Report
ery cylinder described in Test Method B703 that is used t
...

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: B855 − 17 B855 − 22
Standard Test Method for
Volumetric Flow Rate of Metal Powders Using the Arnold
Meter and Hall Flowmeter Funnel
This standard is issued under the fixed designation B855; 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.
1. Scope*
1.1 This test method covers a laboratory procedure for the quantitative determination of the flow rate of a specific volume of a
free-flowing metal powder or lubricated powder mixture.
1.2 Units—With the exception of the values for mass, volume, and density, for which the use of the gram and the cubic centimetre
unit is long-standing industry practice, the values stated in inch-pound units are to be regarded as standard. The values given in
parenthesisparentheses are mathematical conversions to SI units that are provided for information only and are not considered
standard.
1.3 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.
1.4 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:
B213 Test Methods for Flow Rate of Metal Powders Using the Hall Flowmeter Funnel
B215 Practices for Sampling Metal Powders
B243 Terminology of Powder Metallurgy
B703 Test Method for Apparent Density of Metal Powders and Related Compounds Using the Arnold Meter
E456 Terminology Relating to Quality and Statistics
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
2.2 MPIF Standard
MPIF Standard 48 Determination of Apparent Density of Metal Powders using the Arnold Meter
3. Terminology
3.1 Definitions—Useful definitions of terms for metal powders and powder metallurgy used in this standard test method are found
This test method is under the jurisdiction of ASTM Committee B09 on Metal Powders and Metal Powder Products and is the direct responsibility of Subcommittee B09.02
on Base Metal Powders.
Current edition approved April 1, 2017Sept. 1, 2022. Published April 2017September 2022. Originally approved in 1994. Last previous edition approved in 20112017 as
B855 – 11.B855 – 17. DOI: 10.1520/B0855-17.10.1520/B0855-22.
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.
Available from ASTM or Metal Powder Industries Federation, 105 College Road East, Princeton, NJ 08540 and initially reported in MPIF Standard 48
*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
B855 − 22
in Terminology B243. Additional descriptive PM information is available in the Related Material section of Vol 02.05 of the under
“General Information on PM” on the B09 web page.Annual Book of ASTM Standards.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 volumetric flow rate—rate, n—the relation between time and volume of a free-flowing metal powder determined by
measuring the time for a specific volume to flow through the orifice in a Hall Flowmeter Funnel and expressing the ratio in seconds
per 20 cubic centimetres.centimetres (s/20 cm ).
4. Summary of Test Method
4.1 A 20 cm test portion of powder is prepared from the lot to be tested following the procedures in Test Methods B215 and B703.
4.2 This 20 cm test portion is timed as it flows through the orifice in a Hall Flowmeter Funnel following the procedure in Test
Method B213.
4.3 The volumetric flow rate is calculated and reported in seconds per 20 cubic centimetres.centimetres (s/20 cm )).
5. Significance and Use
5.1 The volumetric flow rate is a measure of the flow characteristics of a metal powder. Measuring flow by volume as compared
with flow per unit mass eliminates the variable of the powder density and relates to the production practice of die filling by volume.
5.2 The ability of a powder to flow and pack is a function of interparticle friction. As the surface area increases, the amount of
friction in a powder mass also increases. Consequently, the friction between particles increases, giving less efficient flow and
packing.
5.3 Knowledge of the volumetric flow rate permits the part producer to estimate the number of parts that can be compacted per
hour.
5.4 This test may be part of the purchase agreement between metal powder manufacturersproducers and powder metallurgy (PM)
part producers, or it can be an internal quality control test for any company using metal powders.
6. Apparatus
6.1 Workbench—A level, vibration-free table or laboratory workbench to support the Arnold Meter and the Hall Flowmeter
apparatus.
6.2 Arnold Meter —The steel die block and powder delivery cylinder described in Test Method B703 that is used to obtain the
20 cm test portion of powder.
6.3 Collection Paper—A 6 by 6 in. square sheet of glazed or waxed paper (~150 by 150 mm) used to collect the 20 cm test portion
of powder from the die block of the Arnold Meter.
6.4 Powder Scoop—A small nonmagnetic spoonlike laboratory utensil with handle, having a minimum capacity of 25 cm , used
for the controlled transfer of the 20 cm test portion of powder from the collection paper into the Hall Flowmeter Funnel.
6.5 Hall Flowmeter Funnel —A calibrated Hall flowmeter funnel having a nominal orifice of 0.10 inches (2.5 mm) in. (2.5 mm)
The sole source of supply of the Arnold Density Meter complete with bushing known to the committee at this time is Arnold P/M Consulting Services, 648 Cedar Road,
St. Marys, PA 15857. If you are aware of alternative suppliers, please provide this information to ASTM International Headquarters. Your comments will receive careful
consideration at a meeting of the responsible technical committee, which you may attend.
The sole source of supply of the complete Hall Flowmeter known to the committee at this time is ACuPowder
...