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While sorting through an inventory of new and used Erco and Marchant jaws, I discovered that many are not the same height. Since they wear down and get re-stippled many times -- they can vary as much as 3/8" in height. I also noticed a lot of difference in Erco teeth on the jaws. Many of them, (even many that were marked as pairs), did not mesh properly. I've seen an number of broken jaws, and this problem is what I think could be the cause of many failures. |
This is how the teeth should fit together.
The jaws should be able to close without the teeth binding.
This is how they should NOT look.
Close-up of bad fit.
Jaws are often re-stippled over and over again, which shortens the jaws a little each
time.
If jaw pairs are separated you can end up with a mis-match like the one above.
| If you place the jaws in a jaw block and center them, you can see if the heights match. A slight difference will probably be okay. The above difference is a little too much to overcome. If it weren't so much, the jaw on the right could slide up the ramp a little and and the jaw on the left could slide down a little, in order to make the tops match. This would result in the jaws moving to the right a little, which would be okay, if it were just a slight amount. If this jaw pair above were to be used together, the left jaw would have to slide down so far it would bottom out. this pair will not work together. |
Here's another view of the poor match.
| This is how the jaws should match up. Notice how each of these have been marked the same, which is a good indication that they were previously matched together. |
| If you have any input to add to this page, suggestions or corrections, please e-mail terry@metalshapers.org |
