ASA Fastpitch Softball Bat Size Regulations

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When you want an ASA fastpitch softball bat that meets all the bat size regulations, you might think it's as easy as looking for the certification markings on the bat. Not so: Some regulation-size bats with ASA certification markings are not approved for official ASA play. In addition to checking that your bat meets the ASA size regulations, make sure it's the right fastpitch softball bat for your needs.

Overall Dimensions

An official ASA bat cannot be longer than 34 in. long. It can reach 2.25 in. in diameter at its largest part. The bat is allowed to weigh a maximum of 38 oz. Bats are required to be round to within .05 in. of the diameter.

Grip Size

Fastpitch bats must have a safety grip made of tape, cork or composition material that is a minimum of 10 in. long. The safety grip can extend a maximum of 15 in. from the small knob at the end of the bat. The distance from the safety grip to the knob’s apex cannot be more than .375 in. As long as a bat’s grip is permanently attached to the bat, it can be a molded, finger-form grip.

Safety Knob Specifications

The small knob at the bat’s end, called the safety knob, must be circular or oblong. It must be at least .5 in. larger than the bat handle diameter where the handle meets the safety knob. This sizing includes any width added by the bat’s grip. The angle of the knob’s flat region, which is adjacent to the grip, has to be perpendicular to the bat’s center line within 10 degrees, according to the ASA rulebook.


ASA softball bats must be marked “Official Softball” by the manufacturer and bear an ASA certification mark. However, not all bats that have such markings qualify for use. The ASA publishes a list of banned bats that you must check each year. The ASA also puts forth a list of bats that are approved for play. The list includes the model number, description, manufacturer and ASA inspection date for each bat.