Standard Test Method for Measuring the Coefficient of Restitution (COR) of Baseballs and Softballs

SCOPE
1.1 This procedure is intended to standardize a method of measuring the coefficient of restitution (COR) of baseballs and softballs.
1.2 This procedure is established to provide a single, repeatable, and uniform test method.
1.3 This procedure is for a ball that is intended for use in the game of baseball or softball.
1.4 The test method is based on ball speed measurements before and after impact with either of two test surfaces: wood or metal.
1.5 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 and health practices and determine the applicability of regulatory limitations prior to use.

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Status
Historical
Publication Date
09-Jun-1998
Current Stage
Ref Project

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ASTM F1887-98 - Standard Test Method for Measuring the Coefficient of Restitution (COR) of Baseballs and Softballs
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NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn.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: F 1887 – 98
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
Measuring the Coefficient of Restitution (COR) of Baseballs
1
and Softballs
This standard is issued under the fixed designation F 1887; 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 ball speed is measured before and after impact with the strike
plate.
1.1 This procedure is intended to standardize a method of
measuring the coefficient of restitution (COR) of baseballs and
5. Significance and Use
softballs.
5.1 The ball coefficient of restitution is a ball dynamic
1.2 This procedure is established to provide a single, repeat-
property of relative velocity change caused by impact with a
able, and uniform test method.
rigid wall.
1.3 This procedure is for a ball that is intended for use in the
5.2 This test method is suitable for obtaining data in
game of baseball or softball.
research and development, quality control, and classifying
1.4 The test method is based on ball speed measurements
balls by liveliness.
before and after impact with either of two test surfaces: wood
5.3 Sports associations can use coefficient of restitution
or metal.
standards in specifications for official baseballs and softballs.
1.5 This standard does not purport to address all of the
5.4 This same test procedure can be utilized at impact
safety concerns, if any, associated with its use. It is the
speeds other then that prescribed in this procedure and so noted
responsibility of the user of this standard to establish appro-
in any reported test results.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
6. Apparatus
6.1 Strike Plate, Method A:
2. Referenced Documents
6.1.1 Material, 5.08-cm (2-in.) thick steel.
2.1 ASTM Standards:
2 2
6.1.2 Size, 60.96-cm (24-in. ).
D 1054 Test Method for Rubber Property–Resilience Using
2
6.1.3 Mounting, secured flush to a massive rigid wall of
a Rebound Pendulum
cinder block or concrete, minimally 20.3-cm (8-in.) thick, and
F 1888 Test Method for Compression-Displacement of
3
bolted at all four corners sufficiently secure to prevent move-
Baseballs and Softballs
ment during ball impact.
3. Terminology 6.2 Strike Plate, Method B:
6.2.1 Material, 10.2-cm (4-in.) thick northern white ash
3.1 Definitions of Terms Specific to This Standard:
wood with moisture content between 10 and 15 % with a flat
3.1.1 baseball and softball, n—any ball defined by the rules
smooth surface.
for the game of baseball or softball.
6.2.2 Same as 6.1.2.
3.1.2 coeffıcient of restitution (COR), n—a numerical value
6.2.3 Same as 6.1.3.
determined by the exit speed of the ball after contact divided by
4
6.3 Ball Throwing Device —A ball throwing device capable
the incoming speed of the ball before contact with a massive,
of delivering the ball through the electronic speed monitor at
rigid, flat wall of either wood or metal.
26.82 m/s (60 mph) with a maximum tolerance of 6 0.30 m/s.
4. Summary of Test Method
The machine should be calibrated using the electronic speed
monitor.
4.1 Method A—The strike plate is a rigid metal surface, and
5
6.4 Electronic Speed Monitors —An electronic ball speed
ball speed is measured before and after impact with the strike
measuring system consisting of two vertical light screens
plate.
mounted 30.48 cm (12 in.) apart with a tolerance of 60.32 cm,
4.2 Method B—The strike plate is a rigid wood surface, and
and a photoelectric sensor located at each screen that triggers
1
These test methods are under the jurisdiction of ASTM Committee F-08 on
4
Sports Equipment and Facilities and is the direct responsibility of Subcommittee ATEC, Model “Casey” or equivalent, or a suitable air cannon device, available
F08.26 on Baseball and Softball Equipment and Facilities. from Athletic Training Equipment Co., Sparks, NV.
5
Current edition approved June 10, 1998. Published February 1999. Oehler Research Chronograph, Model 35x2, or equivalent; Oehler Research
2
Annual Book of ASTM Standards, Vol 09.01. Skyscreens, Model 55, or equivalent; available from Oehler Research Inc., Austin,
3
Annual Book of ASTM Standards, Vol 15.07. TX.
1

---------------------- Page: 1 ----------------------
NOTICE:¬This¬standard¬has¬either¬been¬superseded¬and¬replaced¬by¬a¬new¬version¬or
discontinued.¬Contact¬ASTM¬International¬(www.astm.org)¬for¬the¬latest¬information.¬
F 1887
a timing device on ball passage to measure the time for the ball times to a maximum of 12
...

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