The softball bats have a narrow barrel and a long body. The bats are manufactured from wood, aluminium or composite materials like carbon fibre. Softball bats are maximum 34 inches (86 cm) long with 2.4 inches (6 cm) diameter and weigh around 38 ounces (1.1 kg). Some batters prefer small barrels with a shorter diameter as these are ideal for producing high swing speed with a reduced mass. Softball bats resemble baseball bats a lot, especially in the youth level competitions as there's no such difference. But in the senior level game, softball bats are narrower and longer than the baseball bats. 

Types of Softball Bats

• Slow-pitch bats - The slow-pitch bats are comparatively heavier and weigh around 25 to 30 ounces. The bats are harder to swing as compared to fast-pitch bats. These bats are ideal for hitting the ball travelling around 25mph speed.
• Fast-pitch bats - Fast-pitch bats are ideal for hitting the balls travelling with higher speed. These bats weigh around 23 to 28 ounces and can swing faster. The bats are 26 to 34 inches long, composed of composite materials such as aluminium alloy and resemble a lot to the shape of a bottle.
• One-piece bats - One-piece bats are made of a single material entirely and use a single block of wood, alloy or composite material in manufacturing. These bats are stiffer, more robust and widely preferred by the power batters. 
• Two-piece bats - The bat's handle and barrel are manufactured separately and then glued together. The two-piece bats have an advantage of greater flexibility where the head region can swing faster through the hitting zone and adds up the speed. These bats are ideal for contact hitters. 
• Alloy bats - The bats are composed of aluminium and are economically cheaper than the composite bats. These bats don't require additional time for breaking in and can be used right away after the purchase or complete manufacturing.
• Composite bats - The bats are composed of woven fibres which make it lighter and provide the ability to absorb a high quantity of shock produced while hitting the ball. These bats need at least 100 to 200 hits before broken in. 
• Balanced bats - The balanced bat's weight is evenly distributed throughout the bat's body. It offers more swing speed with better control. These bats are ideal for contact or base hitters.
• End-loaded bats - In these bats, the weight is focused towards the end of the barrel leading to increased momentum to strike the ball farther. The end-loaded bats are ideal for strong hitters as they are hard to control.

Evolution of Softball Bats through the years

In 1887, the sport of softball was invented and the bats came into existence. Typically, wooden bats with rubber tip were used to hit the oversized softballs. Later in 1970, a bat manufacturer Worth introduced the first aluminium bats manufactured in one-piece. The idea spread like wildfire and in the late 1970s, a new manufacturer Easton modified the bats by using a high and more substantial grade of aluminium for manufacturing. In 1995, Louisville Slugger and Easton came up with the strongest and lightest grade aluminium softball bats till date.

In 1993, high-performance bats made from single-walled titanium were introduced. The modification included thinner barrels as compared to aluminium bats with good ability to face high-speed balls without denting. Meanwhile, designers kept on experimenting to produce better performance softball bats. They experimented bats with several (two or more) layers of metal or composite hybrids and regarded them as multi-walled bats.

Later in the 2000s, composite bats were introduced and dominated the market as they offer high performance. In recent times, players can choose from a variety of bats such as all-composite bats, bats with composite outer shells, composite handles and aluminium barrels or all-composite double-wall bats.