Bowling Ball Specs

Learning bowling ball specifications can help you better understand bowling ball construction and ultimately help you choose your next bowling ball. Reviewing some of the useful details relating to the manufacturing limits and tolerances will help you become familiarized with bowling ball specifications.




Any bowling ball used in USBC certified competition must be approved and identifiable as a ball listed in the approved bowling ball list at USBC headquarters. A bowling ball must be constructed of solid material without liquids or voids in the centre. Any materials added to or included in the coverstock shall be equally distributed throughout the entire coverstock of the ball. Altering a ball in any way so as to increase its weight or cause it to be off balance outside specifications is prohibited.

The surface of a ball shall be free of depressions or grooves other than holes used for gripping purposes. No foreign material may be placed on the outer surface of the ball. If the surface friction is altered by sanding or polishing, the entire surface must be prepared in the same manner. Plugs, grips, or tape may not extend from the inside of a gripping hole beyond the surface of the ball.


20 other noteworthy specifications:

  • The weight of a ball shall not exceed 16 pounds. There is no minimum weight.

 

  • The surface hardness of bowling balls shall not be less than 72 Durometer D at room temperature (68 - 78 degrees F).

 

  • No chemicals or solvents may be used to alter the surface hardness after a ball is manufactured.

 

  • The circumference of a bowling ball 13 lbs. or greater is 26.7" minimum, 27.002" maximum.

 

  • The diameter of a bowling ball 13 lbs. or greater is a minimum of 8.5" and a maximum of 8.595".

 

  • The Radius of Gyration of a 13 lb. ball or greater is a minimum of 2.46" and a maximum of 2.8".

 

  • The Differential of RG for a 13 lb. ball or greater has no minimum with a maximum of .06".

 

  • The Coefficient of Friction of a 13 lbs ball or greater has no minimum with a maximum of .32 rating.

 

  • The Roundness of a 13 lb. ball or greater is .01" tolerance.

 

  • 5 holes maximum are allowed for gripping purposes, all for the same hand.

 

  • 1 hole for balance purposes is permitted not to exceed 1 1/4" diameter at any point through the depth of the hole.

 

  • 1 vent hole is permitted not to exceed 1/4" diameter.

 

  • No more than 3 ounces difference in 10 lb. balls or greater between the top half of the ball and the bottom half of the ball is permitted.

 

  • No more than 1 oz. difference in 10 lb. balls or greater between the right and left sides of the ball and between the front and back of the fingers holes is permitted.

 

  • Any 10 lb. ball or greater drilled without a thumb hole may have no more than 3 oz. difference between the top half and bottom half of the ball.

 

  • 2 oz. of difference between the top and bottom halves of a ball and 3/4 oz. or less difference from the left to right and front to back of finger holes is permitted in balls weighing between 8 and 10 lbs.

 

  • The centre of the grip of a ball is determined by measuring the cut or front edge of each finger hole to the front edge of the thumb hole.

 

  • Plugs may be inserted into a ball for the purpose of re-drilling the ball.

 

  • Slugs may be used in place of plugging finger holes only when a new hole is drilled completely through the slug.

 

  • There are no colour restrictions for a bowling ball so long as all additives in the coverstock are distributed throughout the entire coverstock of the ball.

 


Since there are no tolerances provided for coverstock texture, the manufacturers of bowling balls offer a variety of textured coverstocks to match with varying oil lane conditions. Therefore, as a bowler, your first decision in choosing a new ball should be the type of coverstock needed to best match with oil conditions where you intend to use the new ball. 


Generally, solid coverstocks are typically pliable and will grip the lane better than a stiff or pearl coverstock. A very aggressive, solid coverstock is designed for heavy oil whereas a a moderately aggressive, solid coverstock will work on medium oil conditions. Of course, your skills as a bowler come into play regarding variables such as rev-rate, ball speed, and bowling ball axis tilt. For dry lanes, using a stiff or pearl coverstock increases ball skid on the front part of the lane and helps conserve energy for the back end of the lane.

Altering the surface texture is certainly permitted so long as the entire surface of the ball is textured the same way. You can wake up the coverstock of a ball by using the services of a pro shop and the high speed ball spinner to apply any grit of pad to the surface of the ball so the texture best matches the oil conditions you are challenged to overcome. The same is true with cleaners and polishes. Use of these substances are permitted so long as the entire surface of the ball is prepared in the same way. You can use USBC approved cleaners during competition and you can clean and polish your ball by hand after competition to prepare the coverstock of your ball prior to using it next time you bowl. 

Selecting the drilling layout is the other factor which will influence bowling ball motion while the ball travels down the lane. There are an extremely high number of scientific layout patterns to choose from that the decision process can be confusing. We recommend you access of "
Drilling Layouts" feature on our home page before doing anything else. Reference the given manufacturer and given bowling ball you have chosen or are considering choosing as your next ball and click on the options provided to access the layout suggestions provided by the manufacturer. You may also review the information about the rev-rate, about the overall shape of motion a given layout will accomplish, and information about oil conditions a given layout matches. 

 


Next, consult with your ball driller and make a joint decision how best to layout the ball for drilling and matching the lane conditions you are targeting. If there is one key factor to consider above all others, then it would be to try and match the break point of the bowling ball to the break point on the lane. The bowling ball break point is controlled by length potential and hook potential ratings of a given ball, by the surface texture preparation, by the layout pattern selected in drilling the ball, and by the individual bowler's abilities. Since the break point of the lane is determined chiefly by the distance and cross lane ratios of oil application by the lane machines settings and by the volume of oil used in the given ratios, the break point down the lane can range from 5-7 feet past the final distance oil is applied to the surface. As a rule of thumb, the break point on the lane is nearer the edge of the lane on shorter distance oil patterns and closer to the centre of the lane on longer distance patterns.

Pin Specs

Everyone should learn about bowling pin specifications. Since knowledge is always key in the path to improvement, let's examine useful bits of information about United States Bowling Congress (USBC) bowling pin specifications.

First, bowling pins are made of hard maple wood and are either plastic coated or constructed in one piece or laminated in two or more pieces? Of course, as pins age or wear from use and constant collisions with bowling balls, there are maintenance procedures allowed by USBC which preserve the life and usefulness of the pins. The use of steel wool or sandpaper to remove dirt and surface splinters and the application of finish and/or the patching of plastic coated pins are permitted but must meet USBC specifications.

bowling pinThe weight of a standard wood pin or a plastic coated pin is not less than 3 lbs 6 ounces and not more than 3 lbs 10 ounces. The average weight pin is about 24% of the weight of a 15 lb. bowling ball. It is easy to understand how a ball will deflect excessively upon contact with a pin if a fairly precise bowling ball angle of entry is not created. Allowing for pin deflection is an important part of strike and spare alignment systems. 

It is also easy to understand that if a bowling ball is not delivered with a sufficient average velocity, either too much speed or not enough speed, the ball will deflect more than a ball deflects if delivered in an optimum speed range. Typically, a ball measured from the release point to impact with the pocket should be between 2.1 seconds elapsed time and 2.4 seconds or about an average speed of 18-21 m.p.h. at release and about 16-18 m.p.h. at impact with the pins. Bowling balls are manufactured to be delivered in this optimum speed range to maximize pin carry and produce a consistent ball motion traveling down the lane.

The height of a bowling pin is 15" but certainly appears much shorter when viewing the pins from the lane approach area. The diameter of the cup at the base of the pin is 3/4". The base diameter of a pin is 2 1/4". The narrowest pin diameter is 1.8" and about 10" above the base of the pin and is sometimes referred to as the "neck" of the pin.

The Center of Gravity of a pin, measured from the bottom of the pin, is 5 5/16" or about one third way up the height of the pin and approximately one inch above the widest pin diameter area of 4.76" measured 4.5" above the pin base. The CG of a bowling pin and the widest part of the pin diameter are both very near the same point where a bowling ball contacts the pin given that the radius measurement of a bowling ball is also about 4.5 inches above the lane surface. 

Because of this, pins can deflect more predictably than one might expect. The bowling ball manufacturing engineers, therefore, can use core and coverstock technology to create ideal ranges of bowling ball entry angles to optimize pin carry. A bowling ball entering the pocket in a straight line parallel to the edges of the lane will deflect more than a ball hooking into the pocket and is at a disadvantage to produce a "strike" result to due to the deflection factor. 

For a right handed bowler, the straight line delivery reduces the ability of the bowling ball to also contact the 5 pin in the second row of pins and the 9 pin in the third row of pins (in most cases the 9 pin and in some cases the 8 pin as well) due to excessive deflection off of the head pin on strike deliveries which also may result in reducing the pin carry and the likelihood of getting a strike.

It is also useful to know something about the pin spots on the pindeck and their relative locations to the edges of the lane and back of the lane. The center of the 7 and the 10 pin spots are located 2.75" from the edge of the lane. The pin spots are 2 1/4" in diameter and must be spaced 12" apart in an equilateral triangle formation.

The 7, 8, 9, & 10 pins center of spot is 3" from the pit at the back edge of the pindeck. The distance from the center of the 7 and 10 pin spots to the nearest kickback panel is 12 1/16". This 12' distance from the kickback panel plus the additional 2 3/4" the ten pin is spotted on the pindeck from the edge of the lane yield total of 15" a pin must travel from the kickback to also contact the 10 pin and produce a strike result. 

The term "weak 10" (for right handed bowlers) refers to the 10 pin remaining standing on a good pocket delivery. Because the pin deflecting off of the right side kick panel (usually the 6 pin) did not make it back to also contact the 10 pin due to the excessive room between the kickback panel and the 10 pin on the pindeck and generally remains in the channel, the bowler thereby leaves the "weak 10 pin" spare to convert. 

The head pin is equidistant from both kickbacks and edges of the lane and is located 34 3/16" from the center of the pin spot to the pit. The overall lane width is 41.5", not including the channel measurements.

With these bowling pin specifications and lane measurements in mind, it is easier to understand how a bowling ball is wide enough to contact both adjacent pins in the same row of pins such as the 4-5 pin combination or the 5-6 pin combination. A bowling ball can deflect enough if it contacts the right edge of the 3 pin to also contact the left edge of the 10 pin for the right handed bowler's "baby split." Same on the left side of the lane with the 2 and 7 pins for left and handed bowlers. 

If, however, a bowling ball hooks too sharply just prior to impact with the 3 pin, then it will not contact the 10 pin as well. That is why most top-flight amateur and professional bowlers will use a cross angle delivery and/or a non-aggressive coverstock bowling ball to avoid the bowling ball hooking too severely upon impact when attempting to convert the 3-10 pin split. We hope you find this pin specification information useful.

 

 

Lane Specs

Learn more information about bowling lane specifications is a good way understand the bowling alignment process and to sharpen your adjustment skills. Let's begin by examining useful bits of information about United States Bowling Congress (USBC) bowling lane specifications.

A regulation bowling lane, including flat gutters, kickbacks, and the approach, must be constructed of wood and/or other synthetic materials which have been tested fully.

The approach extends from and is exclusive of the foul line and shall be an unobstructed level approach not less than 15 feet in length, free from depressions 1/4" or more, and not less than less than the width of the lane. The foul line must not be less than 3/8" nor more than 1" in width, extend across the entire width of the lane at a minimum, and be distinctly marked or embedded between the lane and the approach. 

When a bowler stands the full distance back on the approach with the heels of the bowling shoes positioned at the far back edge of the approach, a distance of about 75 feet exists to the head pin. Many bowlers will take five steps from 15 feet away from the foul line and over-stride to reach the line to deliver the ball leading to poor balance and tempo. Because the approach extends 15 feet back from the foul line does not mean any given 5-step bowler must stand that distance from the foul line when assuming the stance position and getting ready to bowl. 

bowling lane

The set of guides located 12 feet back from the foul line are also useful to align yourself with but do not necessarily indicate that a bowler using either four or five steps stand 12 feet from the foul line. Many bowlers struggle reaching the foul line and therefore release the ball into the approach surface rather than beyond the foul line onto the lane surface where oil conditioner exists to help skid the ball properly down the lane. Why, because of standing too far from the foul line based on their natural stride length. Usually, these bowlers would be better served to move forward on the approach so good balance and tempo can be maintained while walking to the foul line.

The opposite is true for bowlers who do need to stand further from the foul line and get the feet moving more quickly and stretch out steps to achieve improved balance, leverage, and ball speed than standing too closely to the foul line. These are good reasons to consult a certified coach if you are learning to bowl or is you are seeking to improve your game. Make sure your footwork matches best with your natural stride and pace of steps.



Dimensions of the lane are as follows: 

 

  • 1. the kickback is 24" above the pin deck at the highest point and 17" above the deck at a lower point.

 

  • 2. the tail plank is 2" maximum thickness and the pit cushion is 9 7/8" thick.

 

  • 3. the pin spots are fibre spots 2 1/4" in diameter.

 

  • 4. the center of the 7 & 10 pin spots are between 2 1/2" and 3" from the edge of the pin deck and the centers of the pin spots are 12" apart set in a equilateral triangle formation.

 

  • 5. the gutter (channel) width is 9 1/4" in width.

 

  • 6. the gutter is 1 7/8" beneath the lane surface.

 

  • 7. the lane is made of tongue and grooved bed stock.

Typically laid on edge or of a synthetic material giving the appearance of boards sitting on their edges.

  • 8. the centre of the head pin spot is 60 feet plus or minus 1/2" to the foul line.

 

  • 9. the overall length of the lane to the pin deck is 62 feet 10 3/16".

 

  • 10. the lane is 41 1/2" in width.

 



If the lane is 60 feet long from foul line to the head pin where the pocket is located, then it is important to learn that the lane oiling machines typically applies oil to the lane surface with the heaviest concentration of oil from the foul line to about 20 feet distance past the line and from approximately from about the 10th board from both edges of the lane toward the center of the lane (in most house conditions), commonly referred to as the "front-end" of the lane. The second twenty feet of the lane, commonly referred to as the "mid-lane", has a less concentration of applied oil to the lane surface, and the "back-end" of the lane, the final 20 feet of distance to the head pin is clean and dry with no oil applied as to allow the bowling balls to grip the surface of the lane and if the traveling bowling ball axis is tilting, the ball can hook toward the head pin and the pocket.

With this knowledge of the oil distance application by the lane oiling machines, it is easy to visualize why a ball will slide while rolling on the front end of the lane, read the mid-lane, and begin to change direction, or hook toward the pocket, if the bowler applies a release technique encouraging a hook result when delivering the ball as it arrives at the "Break Point" predictably and on the dry portion of the the back end of the lane. The Break Point usually is located about 6 feet distance past the point where the lane machine cuts off oil application across the lane surface, depending on the distance of the oil pattern applied to the lane surface. If a bowler thinks of the lane in three sections down the lane and realizes that there is a graduated friction factor from the front end to the back end of the lane, it will help to visualize how to align initially and select an intermediate target for siting purposes which corresponds to the given oil pattern and to the Break Point down the lane. Naturally, the cross lane ratios of oil applications will determine now near the lane centre or how near the edge of the lane a given bowler will select for initial alignment purposes. A good objective for any bowler is to try and match the Break Point of the bowling ball with the Break Point on the lane.


The surface of the lane must be free of contiguous grooves or ridges, 40/1000" tolerance for crosswise tilt, crowns, and depressions. The lane surface must also have a lengthwise tilt tolerance of 40/1000". 

Older wooden surfaces, twenty or more years old, will likely encounter greater lane depressions or crowns compared to synthetic lane surfaces because of the where the sections of hard maple wood or softer pine wood splice at the end of the front portion of the lane and where the back end of the lane begins and because of the number of cuts to the wood the resurfacing crews have administered over the life of the lane beds. Also, sometimes in the cases with aging or synthetic pin decks which fall out of tilt tolerance, the bowling balls will actually go airborne and will cause increased deflection upon impact with the pins and thereby reduce the effectiveness of pin carry. It is important for the maintenance crew of any given centre to maintain level lane surfaces and level pin decks so the ball will travel without leaving the lane surface and losing velocity.

The lane and approach markings allow for a maximum of 7 guides embedded in or stamped on the approach at each of the following points: 2"-6", 3'-4', 6'-7', 9'-10', 11'-12', and 14'-15'. Seven targets (arrows) may be embedded into or stamped onto the lane 12'-16' distance past the foul line and must be uniform in length and in shape and must be at a maximum of 1 1/4" in width and 6" in length. At a distance 33'-44' beyond the foul line, there may be 4 targets uniform in appearance no wider than a single board nor longer than 36". Each series of guides 6'-7' past the foul line must be parallel to the foul line and circular in shape with a maximum of 10 guides not to exceed 3/4" in diameter. 

The most recognizable and most widely used guides are the targeting arrows about 15 feet from the foul line which are used essentially for intermediate alignment purposes when targeting the pocket some 60 feet away from the bowling ball release point just beyond the foul line. It is obviously easier to select a target nearer you than at a greater distance when aligning initially before making a delivery. Some bowlers prefer using the round guide dots about 6 feet past the foul line rather than the arrows. Using the closer set of guides can be tricky because the guides do not align precisely with the pin formations on the pin deck whereas the arrows do align more closely to the pins set in formation. Consult a certified coach if you have any questions how to achieve a good initial alignment to the Break Point based upon your particular skill set.

The foul light beam is no more than 1/4" beyond the approach, fully automatic, and must be visible between 10-15 seconds duration.

 


No question too many bowlers who complete their footwork slide too far from the foul line out of fear to slide through the foul light beam. Most top professional and amateur bowlers today slide no more than four inches from the line and certainly release the bowling ball onto the lane surface where the greatest concentration of oil is located to help the ball slide effectively down the lane. Visualize the bowling ball entering the lane surface off of a bowlers hand and slightly beyond the foul line at an angle to the lane surface similar to an aircraft making a smooth landing onto a runway as to avoid bouncing the wheels of the aircraft. Releasing the bowling ball behind the foul line at too steep of an angle will produce bounce, inconsistent skid length, and influence the bowling ball to not react as intended.