Replacement of this Window Balance

Question

Marking in grave is: B.S.I 1410

15 inches long metal channel.

The Width of the metal channel is half is 5/8 .

The bottom part is 1 1/8 .

Casey · Accepted Answer

Hello,

It looks like you have the S390-15 channel balance, which uses the 1-1/8" deep 15-001 bottom attachment shown below. Please note that this balance has a 1/2" wide metal channel. 5/8" is not a size that we generally come across for this type of balance. You'll also need a 1410 spring strength option for your replacement balances. Thank you!

Close up view of the S390 balance top.

Close up view of the S390 balance shoe.