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.
Wood / Vinyl Window Manufacturing
Precision Constant Force Balance Systems
Di FLEX 500 BALANCE SERIES
…The most flexible constant force balance system for 1/2” sash windows.
Offers the following:
- Ability to transition from a fixed coil balance to an inverted coil balance by simply changing the mounting orientation and attaching a mounting clip to the coil spring.
- Reduced SKU’s, springs are pre-assembled in holders (singles and doubles), quickly make triple and quad assemblies by connecting the spring assemblies together.
Di FLEX 500 Balance System
1/2" Series Drop-In Balance FIXED CONFIG.
Fabrication Instructions
Di FLEX 500 Balance System
1/2" Series Drop-In Balance INVERTED CONFIG.
Fabrication Instructions
Di FLEX 500 Balance System
1/2" Series Drop-In Balance FIXED CONFIG. 4 Step Assembly Procedure
Di FLEX 500 Balance System
1/2" Series Drop-In Balance INVERTED CONFIG. 4 Step Assembly Procedure
Di FLEX 500 Balance System
1/2" Series Drop-In Balance INVERTED CONFIG.
Clip-less Assy. Procedure
Di Flex 500 fixed assy. demo
Di Flex 500 inverted assy. demo
Di SERIES for 3/4" SASH WIDTHS
…the most technologically advanced Drop-In balance system for hung windows.
Offers the following:
- low cost and a reduction of on-hand inventory
- quiet operation with low operating forces
- superior cam strength & reliability
- higher weight AAMA qualified springs
- Patents: see link above
SFI (Static Friction Inverted) Constant Force Balance System
…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:
- Designed for a one inch pocket
- As few as three SKUs
- Egress achieved
- Low operating forces
- Carrier design provides static friction(eliminates sash drift)
- Patents: see link above
SideLoad™ 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:
- a lower price
- significantly reduced operating forces
- a substantial reduction of on-hand inventory
- dramatically smaller space requirements
- a tighter fitting sash
- Patents: see link above
SideLoad™ Constant Force Balance System for WOOD
the SideLoad™ Balance System - Demo
The SideLoad™ Balance - Sash Removal & Component Review
The SideLoad™ Balance - Sash Guides & NEW Sash Cam Demo
Constant Force Balance Springs
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.
- ½” Series: 3 lb. through 10 lb.
- ¾” Series: 3 lb. through 13 lb.
- ⅜” Egress Series: 4 lb. through 7 lb.
View all related products
Got A Question? Consult our Experts.
Our experts offer a depth of expertise to assist you with all parts of the process. We are ready to answer your questions in a timely manner and will help you define what you need. We produce custom springs for all purposes, and we are here to work with you on any of your customization needs.
