Balance spring replacement

Quick Learner from Murfreesboro Tennessee

Jul 21, 2016 1:47 pm

For double hung tilt vinyl window. Only marking is most likely a serial # si92899. 3/8" but I don't know where to start/stop on measuring the spring length. Top of the coil itself to the bottom of the coil is 27" but there's other parts attached too.

User submitted photos of a window balance.

6 Replies

Paul from SWISCO

Jul 26, 2016 9:29 am

We should be able to help, but I would like you to confirm a couple details. First, what is the length and diameter of the white outer tube? Also, what is the weight of the sash?

Quick Learner from Murfreesboro TN

Jul 26, 2016 11:25 am

The vinyl outer tube also measures 27". How do I determine the weight of the sash? The window measures 57" x 29.5" if that helps.

Paul from SWISCO

Jul 27, 2016 11:46 am

You will need to place the sash on a scale to determine the weight. Also, just to confirm, is 3/8" the diameter of the tube or the inside coil? The most important diameter measurement is for the tube, not the coil.

Quick Learner from Murfreesboro Tennessee

Aug 3, 2016 1:15 pm

The weight of the bottom sash is 14 pounds approximately. The coil is 3/8" but the vinyl cover is about 7/8".

Paul from SWISCO

Aug 4, 2016 11:14 am

Thanks. I would wager the outer cover is actually more like 5/8" or 9/16". I do not believe they make a 7/8" balance but 5/8" and 9/16" are common. I would recommend our S600-27 spiral balance with a red tip option.