ASTM F762/F762M-08(2020)e1

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.
´1
Designation: F762/F762M − 08 (Reapproved 2020)
Standard Test Method for
Determining Change in Groove (or Void) Depth With
Distance Traveled for Passenger Car Tires
This standard is issued under the fixed designation F762/F762M; 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.
ε NOTE—Corrected 9.3 and 11.2 editorially in May 2020.
1. Scope F457Test Method for Speed and Distance Calibration of
Fifth Wheel Equipped With Either Analog or Digital
1.1 Thistestmethodcoversaproceduretobeusedtoobtain
Instrumentation
data for determining the changes in tire tread depth over any
F538Terminology Relating to the Characteristics and Per-
specified course and test period.
formance of Tires
1.2 The tire tread depth loss data obtained according to the
F1016Practice for Linear Tire Treadwear Data Analysis
procedures for this test method may be used to calculate tire
F1502Test Method for Static Measurements on Tires for
tread wear by way of the procedures described in Practice
Passenger Cars, LightTrucks, and Medium DutyVehicles
F1016.
1.3 The values stated in either SI units or inch-pound units 3. Terminology
are to be regarded separately as standard. The values stated in
3.1 Definitions:
each system may not be exact equivalents; therefore, each
3.1.1 break-in, n—one or more periods of initial standard-
system shall be used independently of the other. Combining
ized tire operation during which tire is brought to the state
values from the two systems may result in non-conformance
which will lead to more consistent test results. F538
with the standard.
3.1.2 element, n—an isolated (totally bounded by void)
1.4 This standard does not purport to address all of the
projection. F538
safety concerns, if any, associated with its use. It is the
3.1.3 groove, n—a void that is relatively narrow compared
responsibility of the user of this standard to establish appro-
to its length. F538
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use. 3.1.4 groove (void) average depth, n—the average depth of
1.5 This international standard was developed in accor- all groove depth measurements in a single groove. F538
dance with internationally recognized principles on standard-
3.1.5 groove (void) depth, [L], n—a measurement of the
ization established in the Decision on Principles for the
perpendiculardistancefromarealorcalculatedreferenceplane
Development of International Standards, Guides and Recom-
definedbyedgesoftwoadjacentribsorelementstothelowest
mendations issued by the World Trade Organization Technical
point of contact in the groove (void). F538
Barriers to Trade (TBT) Committee.
3.1.6 irregular wear, n—a type of treadwear characterized
by substantial variations of tread loss both from projection to
2. Referenced Documents
projection and frequently from point to point on a given
2.1 ASTM Standards:
projection. F538
F421Test Method for Measuring Groove andVoid Depth in
3.1.7 measurement interval, n—the distance travelled, in
Passenger Car Tires
kilometres [miles], between two successive groove (void)
depth measurements. F538
This test method is under the jurisdiction of ASTM Committee F09 on Tires
3.1.7.1 Discussion—A specified number of test cycles will
and is the direct responsibility of Subcommittee F09.30 on Laboratory (Non-
constitute a measurement interval. If a tire rotation plan is
Vehicular) Testing.
specified, the measurement interval shall include equal dis-
Current edition approved May 1, 2020. Published June 2020. Originally
tance on each specified wheel position for each tire test
approved in 1982. Last previous edition approved in 2014 as F762/F762M–08
(2014). DOI: 10.1520/F0762_F0762M-08R20E01.
specimen. More frequent measurements may be made if
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
desired. The number of measurement intervals should be
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
compatiblewiththetirerotationplantoresultinalogicalbasis
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. for data interpretation.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
F762/F762M − 08 (2020)
3.1.8 projection, n—apavementcontactingareaofthetread 7. Apparatus
band, bounded by void. F538
7.1 Test Vehicle—Anyvehiclecompatiblewithtestloadand
3.1.9 rib, n—a continuous circumferential projection. F538
tire dimensions.
3.1.10 rotation plan, n— in tire testing, the scheduled
7.2 Rims,ofdesignrimwidth+0.5,−0.0in.forthetesttire
change of wheel positions for all tires on a vehicle, and as recommended by theTire and RimAssociation (T&RA) or
betweenvehiclesinaconvoy,andscheduledchangeofvehicle
other standard tire and rim organizing bodies.
position in a convoy during a road test as appropriate. F538
7.3 Speed Recording Equipment, to record speed history as
3.1.10.1 Discussion—Testtiresshouldoccupyeachposition
a function of time, accurate to 62%.
on the vehicle for the same number of cycles. A tire rotation
7.4 Distance Recording Equipment, to accumulate the total
plan may be designed for each test in accordance with the
test distance, accurate to 62%.
requirement of the test program.
7.5 Vehicle Weighing Device.
3.1.11 test cycle, n—in tire testing, one complete circuit of
the specified test course. F538 7.6 Vehicle Wheel Alignment Equipment (front wheel and,
where applicable, rear wheel).
3.1.12 tread depth average, n— in a single tire, the average
7.7 Tire Pressure Gage.
of all tire groove (void) depth measurements.
7.8 Groove (or Void) Measurement Device (Depth Gage)
3.1.13 void, n—a volume (in the tread band) defined by the
meeting the specifications of the American Gage Design
lack of rubber; the depth dimension of the volume may vary
Committee and Test Method F421.
from point to point in (on) the tread band. F538
7.9 Tread Hardness Gage.
4. Summary of Test Method
8. Test Course
4.1 The tire test procedure is carried out by repeatedly
8.1 Thetestcourseisanynetworkofpublicorprivateroads,
driving one or more test vehicles over a specified test course.
orboth.Aspeedscheduleshallbedefinedaswellasreasonable
All tires on each test vehicle are of the same tire size
number of defined and scheduled stops and starts.
designation: duplicate tires are mounted on each axle. A
break-in period prior to the measurement program is optional.
9. Safety Precautions
The tires may be rotated among wheel positions after comple-
9.1 All normal traffic safety precautions must be observed
tion of a specified number of runs over the test course. Drivers
and appropriate vehicle spacing maintained. Posted and proce-
maintain the same position in the convoy; the vehicle’s
duralspeedlimitsmustbeobserved.Vehiclespacingshouldbe
position in the convoy is rotated uniformly.
at least one car length for each 15 km/h [10 mph] speed plus
4.2 The test consists of a predetermined number of road
three car lengths.
testing cycles. Groove (void) depth measurements are made
9.2 All safety related mechanical and electrical systems of
after completion of a specified number of test cycles.
the vehicle must be in good operating condition for the test.
4.3 The wear rate may by calculated in a number of ways
9.3 Refer to USTMA “Demounting and Mounting Proce-
(see Practice F1016).
dures for Passenger and Light Truck Tires” for additional
safety warnings.
5. Significance and Use
10. Sampling
5.1 Thetestdataobtainedwiththistestmethodmaybeused
10.1 A sample is set of n sampling units obtained from the
to compare the performance of various tires for the conditions
populationbeingsampled.Forexample,thepopulationmaybe
under which they were tested.
aportionofadealer’sstockorasinglelotfromamanufacturer.
5.2 This test method is suitable for a variety of quality
10.2 A sampling unit is a minimum of two duplicate tires.
assurance, research, and development purposes, when tires are
10.3 The test specimen is a single tire of a sampling unit.
to be compared during a single series of tests. The procedure
described may not be suitable for regulatory statutes or
11. Selection
...