Balance Spring for a Side Load Single Hung Window

Question

Good afternoon,

I'm looking to replace two Balance Springs for a Side Load Single Hung window and need help identifying the correct parts. The balance spring is stamped with “32,” (32 Length/50 Weight) but when measuring metal to metal, it seems closer to a “33.” Could you advise which size I should order based on that?

Additionally, I'm unsure about the plastic inserts on each end of the balance spring—can you help me determine which parts I need there? Lastly, do I also need to order the clip that the string attaches to, or is that typically included

Thank you for your help!

Best regards,Chris

Bob · Accepted Answer

Hey Chris. It's a bit confusing, but for standard non-tilt window channel balances like this, those first two digits ('32') refer actually to the height of visible glass in the window, and the metal channel is usually 1" longer than that. So it's totally normal that this is a 33" long balance. Based on the end attachments, this is probably either an S380-33 or S385-33. The only difference between these two channel balances is the depth of the bottom nylon shoe, or the 'heel-to-toe' measurement. See below. Measure your old balance's shoe depth to see what matches best. For a stamp option choose 3250. All of our balances come fully assembled and ready to install out of the box. Let me know if you have further questions.

Comparison of the S378, S380 and S385 balance shoes.