MI 3500 - Replacement Sash Support Coil Balance

Handy Person from Mason, OH

Apr 18, 2020 11:54 am

Hello,

I found a broken coil balance in one of my MI 3500 windows (circa 2000). There are no markings on the coil balance - any idea what replacement part I should order?

6 Replies

Bob from SWISCO

Apr 20, 2020 1:15 pm

Thanks for posting. I'm afraid I can't narrow down what you need from this information alone, as this hardware varies a bit from window to window. Can you show me a picture of the pivot shoe that the coil balances attach to? The identity of the pivot shoe tends to determine the identity of the coil balances needed.

Handy Person from Mason, OH

Apr 21, 2020 10:41 am

Here are a few photos. Let me know if you need more/different images.

1 user uploaded image

Bob from SWISCO

Apr 21, 2020 1:21 pm

This looks like the 15-181 Double Support Detent Clip, which works with the 15-180 Pivot Shoe. This system uses our Series 190 Coil Springs. To know what spring weights you need, look for stamp numbers on the coil tape. If there are none, or you are uncertain, obtain the exact weight of your window sash. Give us that exact weight, and we'll work out what you need.

Handy Person from Mason, OH

May 10, 2020 1:13 pm

I weighed the window sash in question and it was 22 lbs.

Bob from SWISCO

May 11, 2020 7:55 am

If the window weighs exactly 22 lbs, then you'd need a S190-540 5 lb spring and S190-640 6 lb spring on both sides of the sash. This would equal 11 lbs of support on both sides of the window sash, for a total of 22 lbs of support. Let me know if you have any other questions.