Window coil balance

Hello there. The pivot shoe looks like our 15-199. This works with either 1/2" thick Series 160 Coil Balances, or 3/8" thick Series 165 springs. Measure the thickness of your old coil springs to see what matches best. For each replacement spring you need to choose a spring weight, which designates the strength of the individual spring. Look for a stamp near the 'tongue' of the coil that indicates this. If there are no stamps or you are unsure, weigh the window sash. Give me the exact weight, and I can work out what you need. 

Great. Depending on the thickness of the coils, which you did not report, proceed with the following: 

• If the coils are 1/2" thick, then you'll need just (2) of the S160-10 10 pound coil springs, one for each side of the window sash. This will equal 10 pounds of support overall. You can use the 15-150S Single Supports for these coils.
• If the coils are 3/8" thick, then you need (4) of the S165-5 5 pound springs, a pair for each side of the sash. These can be supported with the 15-204 double supports. 

You'll quickly note these are different coil amounts than what you are working with originally, but that doesn't matter so long as the coils are supporting your sash's exact weight. Let me know if you have further questions.