Coil Spring Identification

Question

Just moved into a new (to us) house. It is 20 years old. I have run into a number of these coil spring mechanisms for the windows. I had not seen  these before. A few of them are broken for windows of various sizes. There are no numbers on any of them. The first picture is of a label off of one of the sashes. The pictures of the broken mechanism were taken from a smaller window. Is there a way to tell which replacement mechanisms that I need?

Emily · Accepted Answer

Hello!

Our 15-199 is my recommendation. The 1/2" Series 160 and 3/8" Series 165 are designed to be used with this. To determine the proper coil spring weights, you will have to divide the weight of the sash by the total number of springs in the window. Take a look at the specifications for these parts and let me know if you have any questions.