Balances with odd part number 27C USB

Quick Learner from Longview, TX

Jan 12, 2019 6:38 pm

I have some balances in a non rotating kitchen window that are broken and I can't figure out what a modern match would be.

The house was built in 2004 and I can't find a manufacturer on the windows - but the balance is 1/2" wide and says 27C USB.

3 user uploaded images

6 Replies

Tom from SWISCO

Jan 16, 2019 10:45 am

Thanks for posting. I believe this is either our S390-28 or S351-28, depending on the depth of the bottom shoe. That's the only difference. I personally think it'll be closer to the S351-28, but look it over and see what you think.

In either event, you'd want the 2730 stamp option, which matches your older 27C stamp.

Quick Learner from Longview, TX

Jan 16, 2019 8:48 pm

Thank you very much!

I looked and it looks like the difference in the bottom shoe is 1" for the 351-28's shoe or 1 1/8" for the shoe on the S390 of I'm interpreting the pics right.

I pulled the balance and as luck would have it i'm measuring 1 1/16" - so right in between. I attached a photo in case I'm not measuring it right.

If I. Am measuring at the right spot (the widest as far as I can tell) is it safer to go smaller or bigger? (I don't fully visualize his that shoe functions inside the travel path).

Thank you!

1 user uploaded image

Tom from SWISCO

Jan 17, 2019 9:15 am

Good eye! This information is very helpful. In my experience, you want to go bigger. What probably happened is that your old shoe was 1-1/8" but wore down from use over the years. It happens all the time.

In a worst case scenario, assuming you have a weird kind of shoe that was specifically designed to be 1-1/16" in depth (you never know in this industry), then you can always shave the shoe on the Series 390 down a little. You wouldn't be able to pack out the shoe on the Series 351.

Let me know if you have any other questions.

Quick Learner from Longview, TX

Apr 17, 2020 4:41 pm

Thank you again - it's been a long time but I finally got around to this project - ordered 4 of the Series 390 balances and they worked flawlessly so I'm going to order some more.

Thanks for your expertise!

Tom from SWISCO

Apr 20, 2020 10:09 am

You're welcome! I want to thank you for ordering with us. It means a lot to us.

Please let me know if you had any other questions and we will be happy to help as best as we can.