Steel is an elastic matter and is often used when demonstrating elastic collisions. We also make springs from it.

Due to these properties and for its relative low price, it seems obvious to me to use them to play billiards.

But I don't find any information on the internet about this. Maybe I miss something very obvious?

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    $\begingroup$ At a minimum the rails and the cues would then need to be made of materials just as tough lest the balls damage them. Then there is history...steel was expensive when the progenitor games were developed. That said, I don't see this as a physics questions: it is a question about culture. $\endgroup$ – dmckee --- ex-moderator kitten Jul 15 '12 at 23:05
  • $\begingroup$ @dmckee perhaps... I changed the title so that it looks a little more physics-y, I don't know if that makes a difference. Your call. $\endgroup$ – David Z Jul 16 '12 at 9:03
  • $\begingroup$ "".steel was expensive when the progenitor games were developed. "" Not at all! Ivory was and is much more expensive than steel. Main problem is, that casting of homogenous steel balls was not possible before about 1850. And the meaning is STEEL, not the angloamerican misuse of the word for almost any kind of iron crap. $\endgroup$ – Georg Jul 16 '12 at 16:09

Q: No Steel balls for billiards.. Maybe I miss something very obvious?

A: Yes Steel balls are way too heavy or they weigh too much ;) in both cases they are way, way too much weight.

The density of steel would result in a much lower speed from conservation of momentum of the cue and momentum of the ball. when driving the ball with a fast cue, a much higher shock to the cue tip would occur causing more injuries to players and cue tips, when impacting a ball of significantly greater mass. So the result would be;

  1. more cue tips would break off;
  2. fast breaking cue balls would not be possible with the same light weight cue
  3. More RSI injuries of high impact shock on pool players 4) balls that fly off the table become airborne heavy cannonballs that might cause injury to players standing around the pool table for their next turn. ;)
  • $\begingroup$ The weight is the key I'm missing! :) Playing with 1kg balls is so hard core... $\endgroup$ – Calmarius Jul 16 '12 at 11:20
  • $\begingroup$ Well, you could make them hollow to maintain the mass. It is probably worth discussing: 1. How it would be impractical to construct hollow metal spheres of sufficient symmetry 2. What would the effect of the greater moment of inertia from the ball being a hollow shell ? $\endgroup$ – ThePopMachine Jul 16 '12 at 18:30
  • $\begingroup$ more rotational inertia for same mass and less friction with steel would make for a more boring game as the physics of sides and bottoms and back spin would be less sensitive to "english". It could also be annoying with a less solid hollow golf driver boing sound as the sphere deforms causing unexpected results. The balls are fine and solid and exchange energy fine with the materials used now and have a nice solid muted sound as it should be. Perhaps exotic carbon filled epoxy ceramic hybrids are possible at a $300/ball like my Experimental Yamaha golf drivers 10 yrs ago. I love, but old tech $\endgroup$ – Tony Stewart Sunnyskyguy EE75 Jul 16 '12 at 21:06

From the viewer's perspective, you see collision of balls and hence think of steel as an alternative, which is perfectly alright.

Let us now think how changing the balls to steel will have an impact on the player. (I'm assuming that while changing the material of the ball, the dimensions are retained)

The specifications of a billiard ball can be found here(specs), making the metal ball, $3$ times more massive than its synthetic counterpart. This factor alone influences the game in many ways.

  • For getting the ball from point A to B, the energy imparted should be equal to the energy that will be lost to friction. $E = \frac{1}{2}mv^2=E_{lost\ to\ friction}$. By increasing the mass, not only are you increasing frictional resistance (frictional force is proportional to normal reaction), but also you are making it more difficult to impart extra energy to the ball $E \propto v^2$.
  • This extra energy will have to be given by the player increasing his risk of having wrist injuries.
  • To sustain the impact of the metal ball, the cushions have to be redesigned (which is not really a problem, I guess)
  • Finally the paint. I've seen paint peeling off steel bars so I'm not too sure whether there exists some kind of paint which can sustain such high impact of billiard collision.

On a personal note, I think the part of billiard that I enjoy the most is watching a jump-shot successfully being executed(video). This would be even more difficult with the steel ball.

  • $\begingroup$ Though steel balls may be useful to play snooker, where jumping is not allowed, and it's played with color balls. I think some kind of metal can alloyed to the steel to add some color. :) $\endgroup$ – Calmarius Jul 16 '12 at 11:06

Steel balls would be a lot louder, and would have to be painted. The paint would quickly chip off from constant impacts with other (mostly) unyielding steel balls, looking skanky while providing an uneven rolling surface.

  • $\begingroup$ Why are steel billard balls supposed to be painted? Pétanque steel balls aren't painted and they work fine (for pétanque), even that pétanque is played outdoors on the floor and balls. $\endgroup$ – Pere Jan 22 '19 at 18:29

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