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ITTF Approved 40mm Table Tennis Balls

Top tips to help you choose your ideal table tennis ball.
Part two - What criteria do ITTF approved 40mm balls have to meet.

Part One - Introduction & types of balls | Part Two - Approved 40mm TT balls

Table tennis balls

In part one we looked at the different types of table tennis balls and what the rules say about them.

We also looked at the two most recent major changes made to the ball which affected the size of the ball and the material used to make them.

So let's now take a look at the tests which are carried out on table tennis balls in order to meet the criteria set by the ITTF and then view a list of the balls which appear on the ITTF approved list of balls.

OK, let's get started...

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Tests are first carried out for...

General Appearance

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Butterfly, Stiga, Joola & more

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The ball must be white or orange, and matt, and must appear to be uniform and only have one seam.

The stamp on the ball may cover an area no greater than 280mm² and be printed in one or two colours, but the same colour or combination must be used for all balls of the same brand and the wording must comply with ITTF regulations.

The balls must be packaged appropriately, e.g. in paper or plastic boxes or in a blister pack. And the wording used on this package has to contain either "40" or "40mm" for celluloid balls or "40+" for non-celluloid balls.

The packaging of the balls must also contain a date or a date code and must comply with the ITTF regulations.

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And then there are tests which are carried out on a batch of 24 balls which include the following...

Weight

The official rules state that the ball shall weigh 2.7g, but any weight between 2.67 and 2.77g is acceptable for any one ball. No more than 1 ball out of the 24 sampled may be outside this range. The sample mean must be between 2.69 and 2.76g.

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And its...

Size

The official rules state that the ball shall have a diameter of 40mm.

This is measured using a calibrated electronic device with a precision of at least 0.001mm and which measures the diameter with a precision of 0.01mm.

For celluloid balls the minimum diameter of every ball must be at least 39.50mm, and its maximum diameter must not exceed 40.50mm.

The sample mean average diameter, i.e. the mean of the average of the maximum and minimum diameters for each ball, must be in the range 39.60-40.40mm

For non-celluloid balls the minimum diameter of every ball must be at least 40.00mm and its maximum diameter must not exceed 40.60mm.

The sample mean average diameter, i.e. the mean of the average of the maximum and minimum diameters for each ball, must be in the range 40.00-40.50mm.

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And its...

Sphericity

The official rules state that the ball shall be spherical.

The sphericity of a ball - or more correctly the lack of sphericity - is the absolute difference between its minimum and maximum diameters.

By rotating the ball about its axes, the minimum and maximum diameters are determined. The difference between the two values gives the lack of sphericity.

For celluloid balls the sphericity of any ball must be less than 0.35mm, and the sample mean sphericity must be less than 0.25mm.

For non-celluloid balls the sphericity of any ball must be less than 0.25mm, and the sample mean sphericity must be less than 0.20mm.

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And its...

Bounce

All balls must rebound to a height of not less than 240mm or more than 260mm when dropped from a height of 305mm on to a standard steel block.

For non-celluloid balls all 24 balls must rebound to a height of not less than 240mm and not more than 265mm when dropped from a height of 305mm to a standard steel block.

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And its...

Veer

Veer is a measure of the total sphericity of the ball.

It's measured by rolling the ball down a slight incline onto a horizontal surface, and measuring the distance by which it deviates from a straight line as it rolls across the surface.

The incline is 100mm long at 14 degrees to the horizontal, and on a table that is 100cm long this gives a rolling time of about 3 seconds.

No more than two balls can deviate by more than 175mm from the center-line and each ball is measured at least three times.

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And its...

Hardness

Hardness is measured with a fully automated and computerised tester.

A 20mm diameter pin presses against a pole of the ball and the indentation is recorded to a precision of 0.01mm.

Measurements are made on each pole and the average for the poles provides a measure of the hardness.

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And also the...

Colour and Markings

The colour of the ball must meet the colour specifations which have been set for either white or orange.

The stamp on the ball must also include the following four components:

The ITTF Approval. This may be indicated by the initials ITTF or "ITTF approved", or by using the ITTF logo
the trademark or brand name
the inscription "Made in" followed by the country of production
the inscription "40" or "40mm" for celluloid balls
the inscription "40+" for non-celluloid balls

No other text is permitted.

Buy Your TT Balls Here

Butterfly, Stiga, Joola & more

Click here to view at

Buy Your TT Balls Here

Butterfly, Stiga, Joola & more

Click here to view at

Here's a video showing how the new DHS plastic balls are made and tested in China...

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The following is a list of ITTF approved 40mm table tennis balls valid from 1st January - 31st December 2018.