Constant Force Window Balance Springs
As the world leader in constant force spring technology,
John Evans’ Sons (est. 1850) has produced well over 100 million
high performance window balance products.
As the world leader in constant force spring technology,
John Evans’ Sons (est. 1850) has produced well over 100 million
high performance window balance products.
…The most flexible constant force balance system for 1/2” sash windows.
Offers the following:
…the most technologically advanced Drop-In balance system for hung windows.
…a better option for one inch pocket windows.
Our SFI Constant Force Balance System uses AAMA qualified springs and is a simple conversion from block & tackle.
The SFI Constant Force Balance System:
…a better option for side load windows.
Our SideLoad™ Constant Force Balance System uses AAMA qualified springs and is a simple conversion from block & tackle.
Compared to block & tackle, the SideLoad™ Balance System offers:
Today’s window requirements demand quality and consistency. Springs need to pull their weight…and no less.
Our AAMA qualified springs do just that, no matter how high the rated load.