b 2750-30

Quick Learner from Northwest Berkeley

Jan 11, 2023 3:47 pm

28" long metal channel. these are for blomberg single hung 48" wide by 58"h metal window sash that i think weighs 30-40lbs - they seem to fail easily - should i go up in weight lift?

1 user uploaded image

4 Replies

Emily from SWISCO

Jan 12, 2023 10:47 am

Thank you for reaching out to us. We'd be happy to help but we would need to see photos of the top and bottom fittings for this balance to determine what Series you'll need. Can you also weigh your sash on a scale and tell us its precise weight? That will allow us to confirm the appropriate spring strength.

Quick Learner from Northwest Berkeley

Jan 26, 2023 12:01 pm

thank you. the sash weighs 35lbs and most of the balances seem to be broken. there are a series of smaller windows with same length balances and 25lb sashes and balances are still good. i am attaching pics of the broken balances next to the good balance from the lighter sash.

3 user uploaded images

Emily from SWISCO

Jan 26, 2023 2:09 pm

Great, thank you! It appears you have either our S351-28 or S390-28 balance but the best option ultimately depends on the depth of the bottom shoe as shown in the image below. You'll need to measure the depth of yours to see which one matches up best.

Your original 2750 stamp is calibrated for a sash weighing 26 to 30 pounds which wouldn't be strong enough to support your 35-pound sash. You may want to go with the 2765 stamp instead for your replacements. A pair of balances with this stamp will support a sash weighing 33 to 36 pounds.

Comparison of the S351 and S390 balance shoes.