ASTM F2219-23

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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: F2219 − 14 (Reapproved 2022) F2219 − 23 An American National Standard
Standard Test Methods for
Measuring High-Speed Bat Performance
This standard is issued under the fixed designation F2219; 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 A method for determining bat performance by measuring the bat-ball coefficient of restitution (BBCOR), deriving the ball exit
speedcollision efficiency (e ratio (BESR), ), and calculating a batted-ball speed (BBS). It is applicable to baseball and softball bats
a
of any construction or material. The test methods provide quantitative measures of bat dynamic performance that may be used for
comparison purposes.
1.2 The BBCOR, BESR, BBCOR and BBS are each calculated from measurements taken in the laboratory on test equipment
meeting the requirements defined in this standard.
1.3 Bat performance is found in this standard assuming the bat is unconstrained.
1.4 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.
1.5 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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.6 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:
F1887 Test Method for Measuring the Coefficient of Restitution (COR) of Baseballs and Softballs
F1888 Test Method for Compression-Displacement of Baseballs and Softballs
F2398 Test Method for Measuring Moment of Inertia and Center of Percussion of a Baseball or Softball Bat
F2845 Test Method for Measuring the Dynamic Stiffness (DS) and Cylindrical Coefficient of Restitution (CCOR) of Baseballs
and Softballs
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
These test methods are under the jurisdiction of ASTM Committee F08 on Sports Equipment, Playing Surfaces, and Facilities and are the direct responsibility of
Subcommittee F08.26 on Baseball and Softball Equipment.
Current edition approved May 1, 2022April 1, 2023. Published June 2022April 2023. Originally approved in 2002. Last previous edition approved in 20142022 as
F2219 – 14.F2219 – 14 (2022). DOI: 10.1520/F2219-14R22.10.1520/F2219-23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
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F2219 − 23
3.1.1 balance point (BP), n—distance to the center of mass from the knob end of the bat.
3.1.2 ball exit speed ratio (BESR), n—ratio of ball exit speed to the ball inbound speed plus ⁄2 .
3.1.2 bat-ball coeffıcient of restitution (BBCOR), n—COR of a specific ball colliding with a bat.
3.1.3 batted ball speed (BBS), n—the speed that a ball would be hit off a bat in play based on given pitch and bat speeds.
3.1.4 coeffıcient of restitution (COR), n—measure of impact efficiency calculated as the relative speed of the objects after impact
divided by the relative speed of the objects before impact.
3.1.5 collision effıciency (e ), n—ratio of ball exit speed to the ball inbound speed.
a
3.1.6 cylindrical coeffıcient of restitution (CCOR), n—the ratio of the rebound to incoming speed of a ball impacting a solid rigid
cylinder.
3.1.7 dynamic stiffness (DS), n—a normalized measure of the ball impact force having units of stiffness (lb/in. or kN/m). It is
obtained by dividing the square of the peak force between the ball and impact surface by the ball mass and the square of the
incoming ball speed.
3.1.8 moment of inertia (MOI), n—measure of mass distribution relative to an axis of rotation. It is the product of the mass
multiplied by the square of the distance to the mass, summed over the entire bat.
3.1.9 test sponsor, n—group, association or individual specifying test requirements including ball specifications, performance
measure, and test speed.
4. Significance and Use
4.1 These test methods offer a laboratory means to quantitatively compare the performance of baseball and softball bats.
4.2 Use of these test methods can provide quantitative metrics of bat performance.
5. Apparatus and Equipment
5.1 Test Balls—Baseballs or softballs as determined by the test sponsor.
5.1.1 Ball specification values are to be recorded and traced to individual balls.
5.2 Bat-Ball Test Apparatus:
5.2.1 Ball Cannon—A device capable of shooting a ball at speeds up to 220 ft/s (67.1 m/s, 150 mph). Balls shall be oriented to
impact the strike surface between the stitches. Typical pitching machines cannot yield the aiming accuracy required by these test
methods. Cannon exhaust air must not cause motion of the bat in the absence of an impact.
5.2.2 Ball Speed Gate—Light screens capable of measuring a ball traveling at speeds up to 220 ft/s (67.1 m/s, 150 mph), with an
accuracy of at least 60.7 ft/s (60.2 m/s). The device shall measure across a length of no less than half the ball diameter to avoid
centering error. The first sensor shall be located no more than 12.0 in. (304.8 mm) from the bat surface. The second sensor shall
be located 6 6 0.03 in. (152 6 0.8 mm) after the first sensor (see Fig. 1). The ball speed gate must measure the ball rebound speed.
5.2.3 Ball Angle Measurement—Measure and record the ball vertical and horizontal rebound angles within 1°, using at least one
of the following or equivalent devices.
5.2.3.1 Angled Light Gates—A light trap device capable of measuring the ball rebound angle after impact with a bat (see Fig. 2).
The device shall measure across a length of no less than half the ball diameter to avoid centering error. The vertical rebound angle
F2219 − 23
FIG. 1 Bat Testing Machine
FIG. 2 Diagram Showing Light Gate Arrangement to Measure the Ball Speed, the Horizontal Rebound Angle,
and the Vertical Rebound Angle
F2219 − 23
gate shall be mounted at approximately 45° relative to the inbound ball path. The horizontal rebound angle gate shall be mounted
at approximately 25° relative to the inbound ball path (to provide room for the speed gates). (Appendix X1.)
5.2.3.2 High Speed Camera—A high speed video camera capable of recording the ball rebound path. If a mirror is placed at 45°
atop the light box, one video camera can observe both the horizontal and vertical planes. (Appendix X2.)
5.2.4 Bat Pivot Support—A turntable, rotating in the horizontal plane, with clamps to support and align the bat in the path of the
ball. The rotating clamp and shaft assembly shall not weigh more than 6 lb (2.7 kg) and shall spin freely via ball bearings (see
Fig. 1). The MOI of the clamp turntable assembly shall be determined, recorded, and used in the performance calculations. The
2 2
MOI for the clamp turntable assembly shall not exceed 300 oz-in. (5498 kg-mm ).
5.2.5 Bat Speed Sensor—Device to measure bat rotational speed for at least 100° after impact. Device shall read speeds up to
3000°/s with an accuracy of at least 1°/s (found to be achievable using an optical encoder). Bat speed is taken from the slope of
the linear least-squares fit to the bat rotation versus time data between 5° and 95° after impact.
6. Calibration and Standardization
6.1 Ball Speed Gate—The distance between the sensors of the speed gates should be measured and recorded.
6.2 Reference Standards and Blanks—A standard bat and ball shall be used for monthly reference purposes to verify proper
machine operation.
6.3 Location Tolerance:
6.3.1 Bat—Coat the impact area of the bat with a removable material (dry erase marker or powder).
6.3.2 Ball—Impact the bat with a solid coverless ball such as a pitching machine baseball or softball core.
6.3.3 Location—For each impact, use the average of the ball contact edges on the bat as the impact location. The impact location
is the average location from six balls.
6.3.4 Tolerance—The standard deviation of the six impacts must be less than 0.125 in. The difference between the target location
and the average location from the six impacts must be less than 0.125 in.
7. Conditioning
7.1 Ball and Bat Conditioning and Test Room Conditions:
7.1.1 Test balls shall be stored in an environmentally controlled space for at least 14 days immediately before testing. Wood bats
shall be stored at these environmental conditions for at least 24 h prior to testing. Non-wood bats shall be stored at these test
environmental conditions for at least 2 h prior to testing.
7.1.2 Temperature is to be maintained at 72 6 4°F (22 6 2°C).
7.1.3 Relative humidity (RH) is to be maintained between 40 and 60 %.
7.1.4 Temperature and relative humidity are to be measured and recorded hourly within 60.5°F (60.3°C) and 62 % RH over the
conditioning and test duration.
8. Procedure
8.1 Determination of Bat Features and Test Location—Determine bat balance point (BP) and bat MOI in accordance with Test
Method F2398.
8.2 Select a performance measure (BBCOR, BESR, (BBCOR or BBS) as specified by the test sponsor.
8.3 Bat Test Procedure:
F2219 − 23
8.3.1 Select a test ball meeting requirement of 5.1. Rotate the ball in the cannon between impacts so that the impact area of the
ball is different for each impact. Record the ball weight, compression (Test Method F1888), COR (Test Method F1887), and
circumference. If the results are normalized, record the values of DS and CCOR (Test Method F2845).
8.3.2 Set ball cannon to fire the ball at the desired test speed (60 to 150 mph) as determined by the test sponsor.
8.3.3 Mount the bat in the clamps of the bat pivot support. Locate the bat pivot to provide a ball impact near the maximum
performance location (often 6 in. from the barrel end of the bat).
8.3.4 Locate the
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