Extension Spring #77, 3/8"x6-1/4"x.041WG (Drawer 12)

Extension Spring #77

The 18577 Extension Spring #77 (SRM77) is a durable tension spring designed to provide consistent pulling force in mechanical assemblies, equipment repairs, and general-purpose applications. Made from high-strength spring steel, this extension spring is built to stretch under load and return to its original length once the tension is released. With a 3/8" diameter and 6-1/4" length, it delivers reliable extension performance for mechanisms that depend on steady tension and repeatable movement—because springs should return to work every time, not decide they’re done for the day.

Country of Origin
Varies by production batch

Key Features / Specifications

• Model / Part Number: 18577
• Nominal Size: SRM77
• Product Type: Extension spring
• Material: Spring steel
• Spring Diameter: 3/8"
• Free Length: 6-1/4"
• Wire Diameter: 0.041 WG
• Spring Style: Extension (tension spring)
• Function: Provides pulling tension and return force in mechanical systems
• Construction: Designed for repeated stretching and reliable recovery

Ideal For

• Equipment repair and mechanical assemblies
• Applications requiring consistent tension and return motion
• Agricultural, industrial, or shop equipment
• Maintenance departments keeping replacement springs on hand
• Situations where a spring needs to stretch, pull, and snap back to work without complaining