Casey from SWISCO responded:
June 10, 2020
Hello, You are correct that the (28 4) stamp on your balance would normally indicate a 2840 spring strength option for your S380-29 balances. It is possible that someone replaced your window balances with what they had on hand at some point. If your window sash weighs 16 pounds, I agree that the 2830 would be a better option. As for your top sash guide, start by comparing the dimensions of our 18-166 to yours and let us know how they compare. Thank you! |