What Is My Spiral Balance

Looking for a replacement spiral balance. The existing spiral balance is inside a white plastic tube. The length of the tube is 28 inches and the diameter is 1/2 inch. The cap on the end of the balance is blue. The weight of the window is 20 pounds. The width of the opening in the window where the balance is located is 13/16 of an inch. There are no visual markings on the window or the part. It looks like the part I need is the S600-28 with the blue end. Please confirm. I had previously ordered two S900-27 with a red end. They were too short.

Tom, I double checked the diameter of the plastic tube, and it is at most 9/16", O.D., so it is closer to the 5/8". Initially, I went with the 900 series because the spiral spring inside the plastic tube is 7/16", which is closer to the 3/8", but neither dimension is 3/8" or 5/8". Please confirm the series, length and diameter I should use.

As a follow-up on our discussion, the Series 600 spiral balances seem to work well. The video for replacing the spiral balances was very helpful, but it would have been even better if you would have included a discussion on the operation of the pivot shoe. When the windows are tilted out the pivot shoe gets locked into place. I found it necessary to use a large flat head screwdriver to rotate the round center piece of the pivot shoe to change the location of the pivot shoe. When removing the window or the old spiral balances, the pivot shoe would sometimes slip and need to be adjusted before the window was re-installed. Thank you for the great support!

Tom, the replacement of the spiral balances was going well until I encountered a broken pivot shoe. The top is completely broken out of it. The existing pivot shoe measures 2-3/8" H x 1-1/4" W x 1/2" D. The pivot insert rectangle measures 3/16" X 5/16". It looks like the 15-046 will work as a replacement and is compatible with the Series 600 spiral balance. There is a number on the pivot shoe: 530C. Let me know if you think there is a better replacement. One other point I wanted to mention was the spring tension. Your video suggests about two to three turns on the spring. As I am removing the old springs, I am finding they have about eight turns on the them. I have been using three turns, and the windows seem to work well. Any thoughts? Thanks.

The 15-046 was a good replacement pivot shoe. I used a utility knife to create an opening to remove the old pivot shoe and install the new pivot shoe. The attached pictures show both the left and right sides with the new and old pivot shoes. The left side photo shows the location of the cutout. I also included a picture of the window installed. As you can see, the cutout is not visible. The replacement of all of the spiral balances is complete. All of the windows work well. Thank you for the great support.