Window balance spring assembly for Millard single hung window

Question

Could you tell me which replacement I should use

Casey · Accepted Answer

Hello. It looks like you have either our S380-27 balance or our S385-27 balance. The difference between the the two lies in the shoe.The series 385 balance has the 15-004 shoe which is slightly larger from front to back, as illustrated.

Comparison of the S378, S380 and S385 balance shoes.

If you measure your shoe as it is pictured here you should be able to determine which one you need. Once you have confirmed your balance series, please use the stamp option /sash weight range table pictured beneath your balance to select the correct spring strength option.