Tom from SWISCO responded:
June 24, 2020
The spring sizes have changed, yes. Stamps ending in "90" like yours use an old rating system that is no longer in use. One of our stamps may very well work for you, but you'll need to weigh your sash on a scale to confirm. That's the only way to be sure. |
Tom from SWISCO responded:
June 26, 2020
That's really tough to say. Since it's only a 1/8" difference, it's not always easy to eyeball. I can say that the bottom fitting in your photo does look on the large side, but that's no guarantee. The only way to be sure is to measure it, unfortunately. |