Tom from SWISCO responded:
May 2, 2016
Hello! I wonder if the "33 3" balances were a more recent replacement. They are definitely too weak to support your sash.
How well does the window with "33 4" stamped balances work? If you've never had any issues with it, then I'd say it's a pretty good reference, assuming it's identical in every way. The 3340 is probably a safe option. If you still aren't sure, then you may want to triple check the sash weight. Usually the weight will be a couple ounces one way or the other. If it's slightly under 28 pounds, go with 3340. If it's slightly over, 3350 may be what you want. |
Tom from SWISCO responded:
June 15, 2016
It's possible the heavier window has double strength glass, which would account for the extra weight. Either way, hard numbers don't lie. If one sash is heavier than the other, I would definitely go with the appropriate stamp for either weight regardless of how identical the windows seem.
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