Several innovations have been developed to enhance the performance and durability of aluminum bats. The Fusion softball bat from Dudley Sports Co combines graphite and aluminum. Louisville Slugger’s Air Attack softball bat contains a pressurized air chamber in its hollow core, while its new TPS C405+ is the first triple-wall bat which contains two rings of coiled Springsteel inside the bat. Others are Easton Sports Inc’s bat made of a material used in Soviet aerospace called scandium and Worth Inc’s bats that were made using cryogenic technology.

Metal-bat technology adopts exotic materials and designs for greater swing speed, distance, and durability – but it must limit performance for safety’s sake.

Ever since aluminum bats burst upon the diamond in the 1970s, replacing the familiar “crack” of wood with the jarring “ping” of metal, the industry has turned into an engineer’s high-tech playground. Except that this is a $150 million-a-year big business.

Aluminum has taken over an estimated 90 to 95% of the market, with wood bats remaining largely in the professional major and minor baseball leagues. Why? A hollow aluminum bat (all aluminum would be too heavy to swing) hits harder and farther than a solid wood bat.

An aluminum bat can be made lighter to swing faster, and it can be made with a larger barrel to hit longer. A hollow bat can “give” under ball impact and spring back to its original shape. This “trampoline effect” results in less energy loss at impact and thus greater velocity off the bat. Plus, aluminum bats last longer than wood.

All this has turned an old, traditional industry that crafted ash-blond and grainy, look-alike clubs into a colorful, exciting new arena of engineering innovation, some of it adapted from golf-club development. Competition is spurring exotic new materials and designs, as batmakers strive for increasingly higher performance – meaning greater swing speed and thus longer distances – along with durability.

However, all this development must be done within the rules of the game, now being studied out of regard for the safety of fielders who must react to the lightning speed of balls driven by metal bats and concern over excessive scoring as softball has too frequently become home-run derby. The latest bat technology includes:

* The first bat combining graphite and aluminum, with the barrel end of the graphite composites covered by an ultrathin aluminum sleeve.

* A bat featuring the first use of pressurized air in a chamber, like the air bladder in the midsole of an athletic shoe.

* The first triple-wall bat, with two rings of coiled Springsteel inside an aluminum barrel.

* The first composite bats made with scandium, a rare and expensive metal used in Soviet aerospace, reputed to provide the highest strength of any bat material.

* Bats developed under the cryogenic process, where they are exposed to temperatures as low as -300 [degrees] F to enhance quality and performance.

* An odd-ball bat with a screw-in end that can fit different-weight plugs in order to make “four bats in one.”


The new Fusion bat from Dudley Sports, softball division of Spalding Sports Worldwide, is the first combining graphite composites with C405 aluminum alloy, which Alcoa supplies to all the aluminum batmakers. Dudley developed this bat after another manufacturer struck out with an all-composite model. “That was a great concept but it didn’t have the trampoline effect an all-aluminum bat has,” says John Loiars, product-development manager for Spalding. “We put aluminum in the barrel section for performance (making for a double-wall hitting area) and durability, but have composites in basically the handle and transition areas for light weight and faster swing speed. We can also make this bat stiffer than an all-aluminum one.”

Graphite composites run the entire length of the $299 Fusion bat, while the aluminum sleeve covers 12 in. at the barrel end. This 0.065-in.-thick wall is the thinnest on a soft-ball bat, according to Dudley. (Typical wall on an aluminum baseball bat with high-strength alloys is around 0.110 in.) And for its next-generation Fusion bats Dudley is testing other metals, including titanium. With a titanium sleeve, the Fusion wall would be even thinner.

The present Fusion bat is at least 20% stiffer in bending and 15% more flexible in the barrel than any single-wall C405 bat, resulting in higher energy transfer and increased trampoline effect, the company says. The unique C405/graphite composite design has resulted in a significantly lighter bat, with most of the reduction coming from the handle area. This was achieved without lowering “swing weight,” which is a measure of how heavy a bat feels when swung. A Fusion bat with a 30-oz swing weight actually weighs only 25 oz, Dudley says. A player can swing this bat 3 to 6 mph faster than an aluminum bat with the same swing weight. Result: 10 to 20 ft farther in carry, according to the Chicopee, Mass., manufacturer.

Because of the aluminum/composite blend, Dudley has been able to move the bat’s “sweet spot” or center of percussion 1 to 2 in. farther from the handle for more consistent hits there. This spot, usually 5 to 7 in. from the barrel end of the bat, is the optimum place to hit for maximum energy transfer to the ball and least reaction to the batter.

Batmakers are borrowing from golf-club technology. “The Fusion is basically a graphite shaft with a metal hitting area,” Loiars notes. “We’ve taken almost all the weight out of the handle with a composite and pushed it forward, increasing swing speed.” Like all other bats today, the Fusion is end-loaded, with as much weight as possible shifted to the end. This produces a “sledgehammer effect” from “so much more momentum,” he says.


The Air Attack softball bat from Louisville Slugger, just introduced, also is made of C405 aluminum alloy, but its hollow core contains a pressurized air bladder. “It acts as a spring to reinforce the walls, increase durability, and change the sound and feel of the bat but add only minimum weight,” says George Manning, vice president of technical services for Hillerich & Bradsby Co. Inc., the Louisville finn which has been making bats for 111 years. According to Manning, this bat is the first with air in a chamber inside the bat.

The bladder runs from near the barrel end to the transition portion, where the taper begins and near the label, approximately 10 in. from the handle. The bladder is a plastic material inside a woven textile to protect it from being punctured by any burrs inside the bat. This is done because a bat goes through “amazing distortions” at impact, Manning notes.


Louisville Slugger’s new TPS C405+ Springsteel softball bat ($240) combines a material never before used in bats along with the first triple-wall barrel construction to create what the company calls the largest sweet spot in softball. (This means effective hitting area. Actually, the sweet spot is always a single point. What batmakers do is make the effect of hitting off this optimum spot less punishing or more forgiving.)

Springsteel, the metal used in industrial springs, is known for shape-retaining memory and flexibility. A flat sheet of it is coiled into two wraps and loaded into the barrel end of the bat. Forces are applied to the inner walls of the barrel as the spring tries to uncoil, but are constrained by the bat’s walls. The thinner shell of C405+ is an enhanced version of standard C405 alloy.

Springsteel stores energy and releases it back to the point of impact to propel the ball faster and farther. In addition, the weight of the Springsteel is evenly distributed throughout the barrel, providing a more balanced bat for increased bat speed.

“The Springsteel reinforcement works by distributing the impact load, allowing for the maximum sweet spot and distance,” Manning explains. “Also, Springsteel has three times the tensile strength of C405, providing resilient support to the outer shell and increasing durability.”


Easton Sports Inc., which introduced the first titanium bat (later ruled illegal in soft-ball competition because it performed too well), claims another first. The Burlingame, Calif., company, America’s largest producer of aluminum bats, has the only bats made with Sc500 scandium alloy, which it calls the “the most technologically advanced bat material to date.”

Easton developed the high-performance alloy in conjunction with Ashurst Technology Ltd. and Kaiser Aluminum. Ashurst is a Baltimore company that refines technologies developed in the former Soviet Union and turns them into products for world markets. These bats represent the first commercial use of aluminum-scandium structural alloys outside that country.

Because scandium offers increased strength, durability, plasticity, and fatigue resistance, Easton was able to trim the already thin walls of its Redline Carbon Core baseball bat ($230) and slow-pitch softball bat ($220) another 4 to 7% for “significantly greater performance.”


In Worth Inc.’s new cryogenic Supercell softball and Copperhead baseball bats, the C405 aluminum (which the Tullahoma, Tenn., company introduced in bats last year) is subjected to liquid nitrogen-induced temperatures far below zero to enhance quality and performance. Dan Pitzenberger, vice president of R&D, calls the process a “stress reliever” for bats, improving performance and durability. The process also gives the bats better “pop” and “feel” with an improved sweet spot, the company maintains. (It should be noted that several other manufacturers which have tried cryogenics believe it offers at most a slight improvement in durability.)

The SuperCell Cryogenic softball bat has an extremely light shell and thin wall, and Worth’s Dual Energy Transfer System in which trampoline and springboard effects work together for optimum benefit. The company’s Power Load Suspended Weighting System concentrates more weight in the center of the barrel.

Cryogenics enhances the Copperhead baseball bat which already had the largest sweet spot and longest, largest barrel in the game, Worth says. And a new high-performance end closure prevents flexing on the end, capturing the energy and transferring it back to the sweet spot to maximize trampoline effect.


Since 1990 DeMarini Sports has been making what it calls the only double-wall bat on the market, the Ultimate Distance softball bat. Last year the Easton, Pa., company switched to Alcoa’s new C405 aluminum alloy (from the older CU31). This year it shortened the bat taper from 10 to 8.5 in. to boost swing speed. The barrel is also more rigid to increase trampoline effect.

But it’s the double-wall technology that makes this bat the highest priced of all at $300. According to DeMarini, the Ultimate Distance “outperforms every other bat” because the inner cylinder expands the “incredibly large” sweet spot to 5 to 6 in. from the ordinary single-wall construction’s 1 to 1.5 in.


The new Hollow Point softball bat is the most novel in that it comes with a choice of four end caps or plugs that can be screwed into the barrel end of the bat. A player can change bat weight in seconds – from 24 to 26, 28, or 30 oz. Bombat Sports Inc. claims this end lock of solid aluminum lets the bat be “tolerance tapered,” creating an enormous sweet spot. “All the weight of the plugs is within a half-inch of the end of the bat, producing a sledgehammer effect,” says developer Tony Daddario, vice president and general manager of the Faith, N.C., batmaker.

Bombat claims its new technology outperforms and outdistances any double-wall configuration. However, the $250 Hollow Point is designed for training or recreational use only. The screw-in end makes it presently illegal in competition.


New developments in materials will continue to spur batmakers. Louisville Slugger’s George Manning expects metal matrices and ceramic additions to metals that can enhance without adding weight will eventually be implemented. However, the limits being placed on bat performance and batted-ball velocity are presently causing the industry to focus on other product advantages.

“We must meet BPF (bat-performance factor) standards, so developing exotic materials such as titanium probably doesn’t have the payoff,” Manning observes. “If you could make a bat with an even thinner wall and very light, it would exceed the performance limit. So we and our competitors are looking at ways to stay within these limits but offer some advantages.”

Bat “feel” and “forgiveness” are two areas he believes will become increasingly important. Feel is illustrated by the sting from hitting a ball off-center, particularly on a cold day. Louisville Slugger’s solution is its Sting Stop, an elastomeric material inserted into the hollow handle of a metal bat. For wood bats the company developed a mushroom-shaped plug that floats inside the handle and absorbs vibrations. However, the device is illegal in pro baseball, which demands a one-piece, solid wood bat.

Bat “forgiveness” refers to performance when hit off-center. “If you hit at the sweet spot, the bat feels like it hardly met resistance. But when you hit off the sweet spot, the handle end of the bat goes through some displacement, and you feel it,” Manning says. “With a hollow metal bat we can rearrange the material distribution to change the inertia and stiffness of the bat to prevent that reaction and greatly reduce vibrations.

“There will always be something new,” he concludes. “The competitive nature of the business will force that.”

Bats go under the microscope

Over the last few years, the rules bodies of softball and college baseball have become increasingly concerned about the higher performance of bats, from the standpoint of fielders’ safety and excessive home runs spoiling the game. Titanium was the prime offender, and it was outlawed in competition after it made softball bats lighter than ever before without sacrificing strength. Swing speed and thus ball velocity shot up, and so did distances.

Batmakers have since adopted a laboratory testing method that involves firing a ball at a bat and measuring incoming and rebound velocity. From this the U.S. Slow-Pitch Softball Assn. (USSSA) devised a bat-performance factor (BPF). It’s a ratio of the coefficients of restitution of the ball and bat combination, as compared with a ball rebounding off a concrete wall, for example. The higher the BPF number, the greater the performance. A wood bat typically has a BPF of about 1.0, an aluminum baseball bat about 1.15, and an aluminum softball bat about 1.20, says George Manning, vice president of technical services for Hillerich & Bradsby Co., maker of Louisville Slugger bats.

During the last year the USSSA ruled that a softball bat cannot exceed 1.20 BPF. The Amateur Softball Assn., the other major softball organization, is in the process of determining its standard. And the National Collegiate Athletic Assn. (NCAA) also intends to limit the upward spiral of performance. The NCAA is trying to establish a maximum ball velocity for a batted ball, a tricky task because this depends on many factors, including incoming ball velocity, swing speed, and the exact point of impact on the bat.

Does corking a bat really help?

Some major-league baseball players have “corked!’ their bats, or hollowed them out to insert a cork plug. This lightens a bat so it can be swung faster and hopefully result in greater distance. However, the practice is illegal; baseball rules require solid wood.

But does corking even work? Does it result in greater distance and home runs? No, reports the leading wood bat manufacturer, Hillerich & Bradsby, whose Louisville Slugger models are used by about two-thirds of major leaguers. “In our testing, corking did not make a measurable difference in distance,” says George Manning, vice president of technical services. While corking does make a bat lighter and allow one to swing faster, this advantage is offset by the reduction in mass, which along with velocity determines momentum.

“If you could swing the bat fast enough to offset the reduction in mass, it would increase distance, and apparently a number of players feel it is an advantage. But I think it’s almost all psychological,” says Manning.

What corking does do is weaken a bat, he notes, adding that no batmaker would do it. Any corking done – and Manning believes it is not widespread – is primarily by players’ friends in their home workshops, he believes.

The batter’s box

* A bat used in the professional major and minor leagues must be solid wood, round, and smooth. Its barrel cannot exceed 2.75-in. diameter and length can’t exceed 42 in. Northern white ash is used in over 95% of all wood bats because it has just the proper tensile strength, resiliency, and weight required, reports Hillerich & Bradsby Co. Inc., maker of Louisville Sluggers.

* A bat used in official softball competition must be round or three-sided, smooth, and made of wood, metal, plastic, graphite, carbon, magnesium, fiberglass, ceramic or any other composite material approved by the Amateur Softball Assn. It cannot exceed 2.25-in. diameter at the barrel, 34-in. length, or 38-oz weight.

* A typical major-league wood bat weighs about 2 oz less than its length in inches. Average length is 33 in., and average weight is now 31 oz.

* Most aluminum baseball bats have a 5-oz weight-length differential, and the most popular length in college baseball is 33 in. NCAA rules now allow at most a -5 ratio between length and weight of aluminum bats, meaning a 33-in. model cannot weigh less than 28 oz.

* Nearly everyone in slow-pitch softball uses a 34-in. bat because it’s the maximum allowed. Typical weight is 28 oz and maximum allowed is 38 oz. Fast-pitch softball is played primarily by women, who typically use a 33-in. bat weighing 23 oz.

* Today’s major-league baseball bats are much lighter, with thinner handles and larger barrels, than those of yesteryear. In the 1920s the average big-league bat weighed 40 oz. The heaviest bat ever was 48-oz by Ed Roush. Joe Morgan and Billy Goodman had the lightest, 30 oz. Al Simmons’ 38-in. bat was longest and Willie Keeler’s 30.5-in. model shortest. Ty Cobb and Honus Wagner swung bats that had nearly the same diameter in the handle as barrel.

* Babe Ruth used a 36-in., 42-oz hickory bat. Present star Tony Gwynn of the San Diego Padres tried it once and said, “It felt like I was swinging a telephone pole. I don’t know how anyone could get that thing around on a 95-mph fastball.” Hank Aaron used a similar model to Ruth’s, but it was 35 in. long and weighed 33 oz. Cleveland Indian Julio Franco’s 36-oz bat is one of the heaviest currently in use. Lighter weight is the biggest reason for the continuing increase in cracked bats.

* The most popular bat in the majors today was first ordered by relatively obscure Eddie Malone of the Chicago White Sox: Louisville Slugger model M110. The company makes about 300 different pro models.

* Many materials and designs have been tried in bats over the years. A number of carbon-fiber composite bats have been attempted, but they haven’t been durable enough. There was even a dimpled bat, developed by an M.I.T. professor for improved aerodynamics. It could be swung 3 to 5% faster. However, the rules require a smooth bat, and dimples tend to damage baseballs.

* Keeping the label up (or down, actually) on a wood bat is the way to hit. Hitting on the edge of the grain, which is much stronger, means the bat has less tendency to break. This doesn’t apply to metal bats, of course. In fact, aluminum bats carry printing all the way around so they will be struck on many spots, for longer life.