Window Channel Balance 2030 Specifications

Question

My understanding is that the number 2030 means length of the metal bar and the sash weight. But the site provided different measurements. Please explain.

Thanks

Bob · Accepted Answer

The stamp code really designates two things. The first pair of digits '20' refer to the height of the visible glass in the window. The actual metal channel length is typically 1" greater than this, so that's why you'd need a 21" long balance. The second pair of numbers (sometimes just one number, or even a letter) refers to the calibration of the spring inside the balance--or essentially, the weight range the balance is meant to support. A balance with a stamp option of 2030 is meant to support a window sash in the weight range of 12 through 15 lbs.