ASTM B724-00
(Test Method)Standard Test Method for Indentation Hardness of Aluminum Alloys by Means of a Newage, Portable, Non-Caliper-Type Instrument
Standard Test Method for Indentation Hardness of Aluminum Alloys by Means of a Newage, Portable, Non-Caliper-Type Instrument
SCOPE
1.1 This test method covers indentation hardness testing of aluminum alloys using a Newage, portable, non-caliper-type, hardness instrument which provides readout values numerically equivalent to Rockwell B-scale as determined by Test Methods E 18.Note 1
This is a comparative Rockwell B test and does not provide an actual Rockwell B test value. HRBN, the values obtained from the Newage instrument, are numerically equivalent to Rockwell B values, but do not represent an actual Rockwell B test in accordance with Test Methods E 18.
1.2 This test method measures indentation hardness of heat-treatable aluminum alloys having a hardness from 30 to 100 HRBN, a thickness greater than 1.50 mm (0.060 in.), and pieces too large to be tested by a caliper type instrument. Note 2
This test method covers two instruments (one analog and one digital) which operate differently. Refer to the manufacturer's instruction for proper operation.
1.3 The flat surface size of the area being tested must be compatible with the instrument support area and the material must not deflect during the test.
1.4 The values stated in SI units are the standard. The values given in parentheses are for information only.
General Information
Relations
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:B724–00
Standard Test Method for
Indentation Hardness of Aluminum Alloys by Means of a
Newage, Portable, Non-Caliper-Type Instrument
This standard is issued under the fixed designation B 724; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope gram to Determine the Precision of Test Methods
1.1 This test method covers indentation hardness testing of
3. Terminology
aluminum alloys using a Newage, portable, non-caliper-type,
3.1 Definitions:
hardness instrument which provides readout values numeri-
3.1.1 Definitions of terms relating to hardness testing ap-
cally equivalent to Rockwell B-scale as determined by Test
pearing in Test Methods E 18 shall apply to terms used in this
Methods E 18.
test method.
NOTE 1—This is a comparative Rockwell B test and does not provide
3.1.2 HRBN—The suffix “N,” added to the HRB scale
an actual Rockwell B test value. HRBN, the values obtained from the
designation, indicates hardness numbers derived using this test
Newage instrument, are numerically equivalent to Rockwell B values, but
method which can be related to, but are not necessarily
do not represent an actual Rockwell B test in accordance with Test
identical to, Rockwell-B (HRB) values obtained in accordance
Methods E 18.
with Test Methods E 18. When reporting results derived using
1.2 This test method measures indentation hardness of
this test method, this designation should follow the numeric
heat-treatable aluminum alloys having a hardness from 30 to
value.
100 HRBN, a thickness greater than 1.50 mm (0.060 in.), and
pieces too large to be tested by a caliper type instrument.
4. Summary of Test Method
NOTE 2—This test method covers two instruments (one analog and one 4.1 A portable hand-held and hand-operated instrument
digital) which operate differently. Refer to the manufacturer’s instruction
rests firmly upon an aluminum alloy surface. The manual
for proper operation.
downward movement of the tester in a steady, even and
synchronous manner toward the surface moves a penetrator
1.3 The flat surface size of the area being tested must be
into the surface. Depth of penetration between preload and full
compatible with the instrument support area and the material
must not deflect during the test. load as reflected on the display of the unit, (dial or digital) is an
indication of the hardness value.
1.4 ThevaluesstatedinSIunitsarethestandard.Thevalues
given in parentheses are for information only. 4.1.1 The indicator of dial read-out units is read while the
tester is in the fully depressed position, while the digital
2. Referenced Documents
display of digital read-out units is read when the tester is in the
2.1 ASTM Standards: fully released position, since the reading is automatically
B 648 Test Method for Indentation Hardness of Aluminum locked in at the preload position as the unit is being released.
Alloys by Means of Barcol Impressor
NOTE 3—Another portable non-caliper-type instrument is employed in
E 18 Test Methods for Rockwell Hardness and Rockwell
Test Method B 648. One hand is used to operate the instrument. Hardness
Superficial Hardness of Metallic Materials
numbers are given as Barcol Impressor readings.
E 177 Practice for Use of the Terms Precision and Bias in
5. Significance and Use
ASTM Standards
E 691 Practice for Conducting an Inter-laboratory Test Pro-
5.1 The instrument may be used on a variety of geometries
of aluminum alloy test pieces, providing the surface being
tested has proper support for the instrument.
5.2 This test method is intended for quality assurance and
This test method is under the jurisdiction of ASTM Committee B07 on Light
production control purposes. This test method is not intended
Metals and Alloys and is the direct responsibility of Subcommittee B07.05 on
to be an independent material-acceptance test.
Testing.
Current edition approved June 10, 2000. Published September 2000. Originally
5.3 The thickness of the test piece shall be such that a mark
e1
published as B 724–83. Last previous edition B 724–83 (1991) .
or bulge is not produced on the reverse side of the test piece
Annual Book of ASTM Standards, Vol 02.02.
3 and the test piece does not deflect during the test.
Annual Book of ASTM Standards, Vol 03.01.
Annual Book of ASTM Standards, Vol 14.02.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
B724
5.4 Calibration of the instrument through the use of refer- 7.2 During operation, the indenter is impressed slowly and
ence blocks is required for true comparative hardness values. smoothly into the surface of the material being tested. Lateral
movement or rocking may damage the indenter.
6. Apparatus 7.3 When temperature of test piece exceeds 23°C (73°F),
lower hardness values may result.
6.1 Newage, Portable, Non–Caliper–Type Instrument, con-
taining means of applying the desired loads, an indenter and an
8. Test Piece
indicating device. This instrument interacts through hand
8.1 The test piece shall be a portion of the material whose
power and spring load to indent.
area is suitable for testing (see 8.2 and 8.3).
6.1.1 The indenter of dial read-out units shall consist of a
8.2 The surface area of the material in contact with the base
carbide tip bonded to a threaded shaft. The tip is conical, and
area of the testing device must be free of debris and extreme
it shall have an included angle of 110.0 6 1.0°. The top of the
irregularity.
cone shall possess a flat surface of 160.0 6 10.0 µm in
8.3 The contact area of the indenter shall be smooth, clean,
diameter. The indenter of digital read-out units shall consist of
and free of mechanical damage. The surface may be lightly
a diamond bonded to a threaded shaft. The tip is conical, and
polished to eliminate die lines, scratches, laps, seams and
shall have an included angle of 100° 6 1° and a flat area of 62
surface cracks prior to hardness testing, provided the surface
6 2 µm in diameter.
hardness is not affected. A surface finish of 3.2 µm or finer is
NOTE 4—A single indenter and load combination are used in each
recommended.
instrument. The combination of load and indenter produces a result
9. Calibration
numerically equivalent to Rockwell B.
9.1 Calibration of Aluminum-Alloy Reference Hardness
6.1.2 A dial scale having graduations of at least every two
Blocks—Using a Rockwell bench-type machine, calibrated in
hardnesspoints,HRBNshallindicatehardnessondialread-out
accordance with Test Methods E 18, an aluminum-alloy refer-
units. Digital read-out units shall have a digital display
ence block should be tested and calibrated in accordance with
resolution of 0.1 hardness points HRBN. The range of either
that method. Using the “B” scale, uniformly distribute five
unit shall encompass at least from 30 to 100 HRBN.
impressions within a 50 mm by 50 mm (2 by 2 in.) area of the
6.1.3 For each hardness point, HRBN, the penetration of the
reference block. Read the dial of the Rockwell-type bench
indenter of a dial read-out or digital read-out unit can be
machine to the nearest 0.1 HRB value. The difference between
estimated from Fig. 1. This relationship may vary with the
the largest and smallest of the five readings (repeatability) shall
alloy and temper being used.
not exceed 1.5 HRB units.
6.1.4 The dial read-out test instrument shall apply a preload
of 4 N and a full load of 49 N, while the digital unit shall apply
NOTE 5—The Rockwell bench-type machine should also be calibrated
a preload of 12 N and a full load of 49 N.The hardness number
using NIST traceable Rockwell B test blocks, when these become
is the distance traveled by the penetrator between the pre-load
available.
and full load, as indicated on the dial of the instrument.
9.1.1 The 50 mm by 50 mm area of the reference block
which contains the five calibration hardness impressions shall
7. Hazards
be suitably delineated at its boundaries and designated as the
7.1 This instrument is delicate. Extended use in a substan- Newage, portable instrument, calibration area. Mark the refer-
tially dusty or corrosive environment may lead to erroneous ence blocks with the average of the five hardness readings
results. made in accordance with 9.1.
FIG. 1 Depth of Penetration in Rockwell B Tests of Some Brass
B724
NOTE 6—Reference Hardness Blocks used to calibrate the Newage
10.3 For curved surfaces, use an
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.