Is this jewel usable?

Wayne,

It looks like there is a very tiny nick on the top side of the hole. I take it that it is a top plate jewel for either a center, third or forth wheel. If this is the case, it could be used if a replacement isn't at hand. I would not use it in either balance or escape wheel pivots.

If the chip was deep enough that it causes a rough bearing surface closer to the shoulder of the pivot, I would replace it. It could cause poor oil distribution or excessive wear on the pivot.

Mike Miller

If that's a train jewel (and I'm pretty sure it is), and if I didn't have a replacement or a practical way of getting one, I'd determine which side of the hole the pivot normally runs against, and install the jewel so that the chip is on the opposite side.

Pressure on train wheel pivots always forces them toward only one side of their bearing (or jewel), while never touching the other side. If a jewel or bushing is worn, or has some sort of fault on one side, the simple solution is to turn it a half round so that the side with the fault is opposite where the pivot runs.

====================

Steve Maddox
President, NAWCC Chapter #62
North Little Rock, Arkansas
IHC Charter Member 49

Mike & Steve
Thanks for the advice about the jewel - there is a small crack - so think I will look for a replacement.