The maximum legal diameter for bats shall be 2 3/4".

Subject to the following, in addition to wooden bats, metal bats shall be allowed in Rep play.

For all 12U and 13U play, metal bats with (i) a 1.15 BPF (Bat Performance Factor) or (ii) USA Baseball Model is permitted. For this division using up to a minus 10 length/weight differential is permitted.

For all levels of play 14U and above, only wood bats, bamboo bats and wood composite bats will be allowed. Wood composite bats include wood bats with fibreglass sheathing and wood barrelled bats with composite handles. Wood composite bats do not include any bat that has any metallic component.

 

• For 14U and 15U play, wood bats and non-wood bats may be used. Only non-wood bats with a length-to-weight differential of -5 or less are permitted.
• For all levels of play 16U and above, only wood, wood composite, and wood-like material bats are permitted. Wood composite bats include wood or bamboo bats with fiberglass sheathing and wood barrelled bats with composite handles. Wood composite bats do not include any bat that has any metallic component.

18U & 21U levels will use Wood or Wood composite bats with a maximum minus 3. The minus 5 bat restriction applies for 15U level only. 

Where metal bats are permitted, Baseball Ontario allows the use of BESR certified bats and BBCOR certified bats in Baseball Ontario play, and to accept the NCAA's list of BBCOR certified bats and the NFHS’s list of BESR certified bats, with the understanding the lists may be modified from time to time. Solid wood bats are always approved for Baseball Ontario play. For the purposes of the OBA Bat Rule, bamboo bats are wood bats; and composite wood bats are wood bats. Metal/wood bats are not considered wood bats and cannot be used at 14U and above. Hollow aluminum alloy bats (Class A in the lists) are only allowed for Baseball Ontario play at 13U and below.