ASTM F2219-02e1

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An American National Standard
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Designation: F 2219 – 02
Standard Test Methods for
Measuring High Speed Baseball Bat Performance Factor
This standard is issued under the fixed designation F 2219; 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.
e NOTE—Sections 1, 3, 5, 7, 8, 9, and 10 were editorially updated in February 2003.
1. Scope 3.1.3 ball exit speed ratio (BESR), n—ratio of ball rebound
velocity to ball inbound velocity plus one-half, as determined
1.1 This specification defines a method for determining the
by this test method.
Bat-Ball Coefficient of Restitution (BBCOR), Bat Performance
3.1.4 bat-ball coeffıcient of restitution (BBCOR)—the COR
Factor (BPF), Ball Exit Speed Ratio (BESR), and a method for
of a specific ball colliding with a bat as defined in this test
estimating the Batted-Ball Speed (BBS). It is applicable to
method. See coeffıcient of restitution (COR).
baseball bats of any construction or material. The method
3.1.5 bat performance factor (BPF), n—the ratio of perfor-
provides a quantitative measure of bat dynamic performance
mance a bat introduces to a ball collision, compared to a ball
that may be used for comparison purposes.
colliding with a solid steel half cylinder as defined in this test
1.2 The BBCOR, BPF, BESR, and BBS are calculated from
method.
measurements taken in the laboratory on test equipment
3.1.6 center of percussion (COP), n—also known as the
meeting the requirements defined in this specification.
center of oscillation, the length of a simple pendulum with the
1.3 The values stated in English units are to be regarded as
same period as a physical pendulum, as in a bat oscillating on
the standard.
a pivot. Forces and impacts at this location will not induce
1.4 This standard does not purport to address all of the
axial reactions at the pivot point.
safety concerns, if any, associated with its use. It is the
3.1.7 coeffıcient of restitution (COR), n—a measure of
responsibility of the user of this standard to establish appro-
impact efficiency calculated as the relative speed of the objects
priate safety and health practices and determine the applica-
after impact divided by the relative speed of the objects before
bility of regulatory limitations prior to use.
impact.
2. Referenced Documents
3.1.8 distal node, n—flexible body property in first mode of
vibration (two node case), defined as the furthest node from a
2.1 ASTM Standards:
reference (hands or pivot point in the case of a bat). The node
F 1881 Test Method for Measuring Baseball Bat Perfor-
is where vibrational amplitude is minimized or zero.
mance Factor
3.1.9 maximum energy transfer point, n—result of rigid and
F 1887 Test Method for Measuring the Coefficient of Res-
flexible body properties, point along a bat where maximum
titution (COR) of Baseballs and Softballs
batted ball speeds result. For typical bats, this point is located
F 1888 Test Method for Compression-Displacement of
close to the COP.
Baseballs and Softballs
3.1.10 moment of inertia (MOI), n—a measure of mass
3. Terminology
distribution relative to an axis of rotation. It is the product of
the mass multiplied by the square of the distance to the mass,
3.1 Definitions of Terms Specific to This Standard:
summed over the entire bat.
3.1.1 balance point—the distance to the center of mass
3.1.11 period, n—the time required for a pendulum to
measured from the distal end of the bat knob.
oscillate through one complete cycle.
3.1.2 ball exit speed (V ), n—outbound speed (in mph), of
f
3.1.12 sweet spot, n—produced by a combination of rigid
ball following impact with a bat as defined in this test method.
and flexible body properties, a point on a body where an impact
results in a minimum vibrational energy at a given reference
This test method is under the jurisdiction of ASTM Committee F08 on Sports
location (in the case of a bat, hands or pivot point). For typical
Equipment and Facilities and is the direct responsibility of Subcommittee F08.26 on
bats, the sweet spot is generally located between the COP and
Baseball and Softball Equipment and Facilities.
the distal node.
Current edition approved Dec. 10, 2002. Published February 2003.
Annual Book of ASTM Standards, Vol 15.07.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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F2219–02
FIG. 1 MOI Fixture
4. Significance and Use 5.2.1 Compression—300 to 375 lb at ⁄4 in. deflection (1135
to 1668 N at 6.4 mm). Compression values determined per Test
4.1 This test method offers a laboratory means to compare
Method F 1888. Balls to be labeled with compression values.
the performance of bats at a greater level of bat-ball impact
5.2.2 Weight—5.0 to 5.25 oz (142 to 149 g).
speeds than provided by Test Method F 1881.
5.2.3 Size—9 to 9.5 in. circumference (22.9 to 24.1 cm).
4.2 Use of this test method can provide sports governing
5.2.4 High Speed Ball COR—Shall be measured in a
bodies a means to compare the anticipated batted-ball speed,
manner similar to Test Method F 1887 except that the impact-
thus batted-ball distance for the purposes of controlling the
ing surface shall be a solid steel half cylinder of 2 ⁄8 in. (66.7
game.
mm) diameter and test speed is 132 6 1.3 ft/s (40.2 m/s 6 0.4
m/s, approximately 90 mph). COR shall be determined for each
5. Apparatus
ball at the appropriate test speed. Balls to be labeled with COR
5.1 Bat Center of Percussion Test Apparatus:
and test speed in fps.
5.1.1 Ruler, suitable for measuring lengths up to 42 in.
5.3 Bat-Ball COR Test Apparatus:
(1067 mm) to the nearest 0.031 in. (0.79 mm).
5.3.1 Ball Cannon—A device capable of shooting a ball at
5.1.2 Weight Scale, suitable for measuring weight up to 48
speeds up to 135.0 ft/s (41.1 m/s) with a maximum aiming
oz (1360 g) to the nearest 0.0035 oz (0.1 g).
error of 60.125 in. (63.2 mm) at the point of impact. The ball
5.1.3 Electronic Timer, suitable device sufficiently accurate
shall not have a spin rate in excess of 50 rpm. Typical pitching
for measuring time to the nearest thousandth of a second (0.001
machines cannot yield the aiming accuracy required by this test
s).
method. Cannon exhaust air must not be allowed to pass to the
5.1.4 Stand—A frame large enough to allow a bat held in a
bat. The ball cannon can be any distance from impact location,
vertical position to swing freely (see Fig. 1).
as long as it can meet the ball aim requirements and provide six
5.1.5 Collar-Clamp—A lightweight clamp or collar that can valid impacts in 12 shots or less.
hold the weight of a bat and provide a fixed pivot location.
5.3.2 Ball Speed Gate—A light trap device, or an equiva-
Collar shall be rotationally balanced (see Fig. 1).
lent, capable of measuring a sphere traveling at speeds in
5.2 Test Balls—Official baseballs approved for play and excess of 135.0 ft/s (41.1 m/s) with an accuracy of 1.35 ft/s or
tested in accordance with the following procedures. better (0.41 m/s). The device shall measure across a length of
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F2219–02
FIG. 2 Bat Testing Machine
no less than half the ball diameter to avoid centering error. For 6.2 Reference Standards and Blanks—A standard bat and
example, the device shall sense an object across a 2 in. (5 cm) ball used for reference purposes shall be used to verify proper
line. The first sensor shall trigger when the ball is no more than machine operation.
18 in. (45.7 cm) from the bat surface. It is suggested the second
sensor shall trigger 12 in. (30.5 cm) away from the first and
7. Conditioning
must not be any further than 14 in. (35.6 cm) away. The
7.1 Ball and Bat Conditioning:
distance between sensors must be measured and maintained
7.1.1 Balls and wood bats shall be stored at the test
within 60.005 in. (60.13 mm). The device must be able to
environmental conditions for at least 24 h prior to testing. Non
measure the rebound speed of the ball after impact with the bat.
wood bats shall be stored at the test environmental conditions
This requires the device reset and arm quickly enough to
for at least 2 h prior to testing.
capture the ball travelling back through the speed gate.
7.1.2 Temperature is to be maintained at 72 6 4°F (22 6
5.3.3 Bat Pivot Support—A turntable with clamps to sup-
2°C).
port and align the bat in the path of the ball. The clamp surfaces
7.1.3 Relative humidity is to be maintained at 50 6 10 %.
shall be a 45° Vee clamp with a radius no greater than 2 in. (5
7.1.4 Bats and balls are to be tested within 1 h after removal
cm). The rotating clamp and shaft assembly shall not weigh
from controlled area.
more than 6 lb (2.7 kg) and shall spin freely via ball bearings
7.2 Test Room Conditions:
(see Fig. 2). The polar Moment of Inertia (MOI) for the clamp
7.2.1 The test room will be controlled environmentally.
2 2
turntable assembly shall not exceed 192 oz-in. (35117 g-cm ).
7.2.2 Temperature is to be maintained at 72 6 4°F (22 6
The actual Moment of Inertia of the clamp turntable assembly
2°C).
shall be determined and used in the performance calculations.
7.2.3 Relative humidity is to be maintained at 50 6 5%.
6. Calibration and Standardization
8. Procedure
6.1 Ball Speed Gate—The distances between the sensors of 8.1 Determination of Bat Features and Test Location:
the speed gates must be known and recorded to the stated 8.1.1 Weight—Measure the weight of the bat to the nearest
tolerances. The accuracy of the timers used in the velocity 0.0035 oz (0.1 g).
sensors must be adequate to provide the stated velocity 8.1.2 Balance Point—Measure and record the overall bat
accuracy at maximum stated speeds. The timers used shall be length to the nearest 0.031 in. (0.79 mm). Place bat on balance
calibrated on a yearly basis. A certificate of calibration for point stand as shown in Fig. 3. Adjust height of knob stand to
distance measurement tools and the timers shall be included keep bat axis level. Knowledge of the knob and barrel
with the test report. diameters can be helpful here. Measure and record the barrel
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F2219–02
FIG. 3
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