spiral window balance

A home owner from USA says:
I am hoping you can help me.

I have a house and all the windows seems to have the spiral block.
I measure it and it seems to be 17.5... but, I dont even see that in your website.
I am attaching a couple pictures.
they are old windows.

please help
Spiral window balance
Profile picture of Paul
Paul from SWISCO responded:
Unfortunately the company that made your balance system has gone out of business. That said, I believe that our S500-18 spiral balance can work as a substitute. You would also need a balance bracket like our 17-012 to attach it to the sash. The brackets hooks onto the end of the balance spiral.

Installing can be a bit tricky, but we can help. With someone helping you, you will need to drop the new balance in from the top of the sash, screw it in at the top, then let the spiral drop down. You will then raise the sash and, while someone holds the sash in the open position, spin the spiral up to the bottom of the sash. Finally, with our 75-004 tool, give the balance about three turns to charge it and lock it to the end into the sash clip.

Let me know if you have any more questions.
17-012 : Bracket, #32
Bracket, #32
67-002 : Screw-on Face Guide
Screw-on Face Guide
S500-18 : 18
18" Series 500 Spiral Balance
33-017 : #8 x 1
#8 x 1" SS Philips Pan Head Screw
33-090 : #8 x 3/4
#8 x 3/4" Philips Pan Head SS Screw
33-098 : #5 x 3/8
#5 x 3/8" Oval Head Screw
How to Identify a Replacement Spiral Balance
How to Identify a Replacement Spiral Balance
How to adjust a spiral balance on a non-tilt window
How to adjust a spiral balance on a non-tilt window
How To Choose the Proper Spiral Balance Tip Color
How To Choose the Proper Spiral Balance Tip Color
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