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Tow balls, what are they made of?
Brooky - 17/5/11 at 02:32 PM

And before any smarty pants jumps in, I know they are steel...... so no cheese, wood or other funny comments ta! LOL

Right, now that's out of the way, pretty much as the topic says. What are they the swan neck type ball thingy's made of? What grade steel?
The reason i ask is because we had to remove one the other day at work, one of the guys swears blind they are high tensile steel, but our 18v dewalt saw cut through it so I think its a much lower grade. It was solid metal, about two inch diameter.

Any thoughts welcomed...

tegwin - 17/5/11 at 02:38 PM

Its not high tensile...

I have seen cast steel swan-necks and towballs..

Its just mild steel.... Some might have a case hardening of some description to limit wear on the surface of the ball...

avagolen - 17/5/11 at 02:53 PM

I do not know either

But I do know that there are different loadings.

I have used a hacksaw to remove the 'ball' recently with no trouble.

Len.

balidey - 17/5/11 at 03:02 PM

Well I saw one once that looked like it was made from a tennis ball.

Now a serious bit.
High tensile gives you a clue. Tensile. ie its good in tension.
You can still cut high tensile steel fairly easily. Its hardness that makes something more difficult to cut.

AndyW - 17/5/11 at 03:17 PM

quote:
Originally posted by balidey
Well I saw one once that looked like it was made from a tennis ball.

Now a serious bit.
High tensile gives you a clue. Tensile. ie its good in tension.
You can still cut high tensile steel fairly easily. Its hardness that makes something more difficult to cut.



+1

britishtrident - 17/5/11 at 03:18 PM

One manufacturer product spec list it as "drop forged carbon steel" ---- I would guess 0.45% C , 0.90% Mn, 1% Cr much the same stuff used to make automotive steering parts and connecting rods but I am willing to bet some will be to much lower specification.

[Edited on 17/5/11 by britishtrident]

britishtrident - 17/5/11 at 06:03 PM

quote:
Originally posted by balidey
Well I saw one once that looked like it was made from a tennis ball.

Now a serious bit.
High tensile gives you a clue. Tensile. ie its good in tension.
You can still cut high tensile steel fairly easily. Its hardness that makes something more difficult to cut.



Yes in terms of the metal of the blade cutting into the surface but high tensile implies high sheer, so the effort to sheer off metal with each cut increases.

If you were cutting a high tensile bar with a mechanical hack saw it would take the same number of strokes but the energy required for each cut would be more.