Is there something that squishes right at the bottom when force is applied? Because I was pushing my calipers all the way to the end. I do not see how a 33mm mark WOULD EVER come up all the way to the fitting.

Considering how every tutorial and instruction harps on about how you are supposed to mark the depth and go all the way, this creates an incredibly confusing situation for the person who actually tries to follow the steps.

Am I doing something wrong?


enter image description here

  • Please post s photo of the pipe. Are you measuring internal or external diameter Mar 12, 2023 at 5:30
  • I am not measuring diameter. I am measuring depth. This has nothing to do with the type of pipe. I am claiming that all of these fittings are too shallow to EVER reach the spec of 33mm insertion depth. Mar 12, 2023 at 5:33
  • 3
    I notice you left in the plastic stiffeners. Those are used only with PEX or other soft pipe, probably the depth figures do not take those into account. I've never heard of anyone trying to get a measured depth, folks just shove the pipe in till it stops.
    – kreemoweet
    Mar 12, 2023 at 7:08

1 Answer 1


I have found that the pipe can be pushed in until it hiots the bottom - which is the full depth you measured.

Then the pipe always comes out a small amount - as the seal and teeth start to grip properly. That may be the 2mm measured.

I mark my pipes and as long as the mark is within 3mm then it works fine. The ones where the marks is 5 or 6mm away, I need to recut the pipe and check for obstructions.

Not the answer you're looking for? Browse other questions tagged or ask your own question.