What are the current rules and regulations regarding Fastpitch softball bats?

All fastpitch softball bats must have a 2 1/4 inch barrel diameter and must not be over 34 inches in length and 31 1/2 oz in weight regardless of which association you play in.

ASA

Bats must be marked with the ASA Certified 2004 stamp. These bats should perform within the limits of the 98 mph batted ball speed standard. Bats can be made from aluminum or other metals; fiberglass, graphite or other composite material; or wood. Bats can be made from one or multiple pieces

USSSA

Bats may not exceed a Bat Performance Factor (BPF) of 1.20. This should be marked on most, if not all, bats. Bats can be made from aluminum or other metals; fiberglass, graphite or other composite material; or wood. Bats can be made from one or multiple pieces.

Other Organizations

ASA is generally considered the most highly regulated association in softball, followed by USSSA. If your fastpitch softball league is governed by a different body, chances are that if your bat bears the approval of either ASA or USSSA, it will be legal in your league. That being said, it is always a good idea to check with your league's website or director for specific rules, regulations and lists of approved bats.