Description
The PRIME LINE PRODUCTS SP 9639 is a single loop extension spring designed for general handyman and maintenance applications. Constructed from durable spring steel with a nickel-plated finish, this spring delivers reliable tension and corrosion resistance in both indoor and outdoor environments. Key dimensions include a 9/16 inch outside diameter, a 29/64 inch inside diameter, and a 16-1/2 inch length with a 0.054 inch wire diameter. The spring is rated for a maximum safe load of 9.5 pounds and a maximum deflection of 25.2 inches. Each package contains 3 springs sold as a unit.
This extension spring suits a wide range of light-duty repair and replacement tasks including screen doors, storm doors, garage equipment, and general mechanical assemblies. The nickel-plated finish resists corrosion, making it appropriate for use in humid or exposed environments. Tradespeople and maintenance professionals working on residential and light commercial properties will find this spring a practical stock item for service calls requiring quick spring replacement.
Key Features
- Spring steel construction provides consistent tension and long service life
- Nickel-plated finish resists corrosion for indoor and outdoor use
- Single loop ends for straightforward hook or pin attachment
- Maximum safe load of 9.5 pounds with up to 25.2 inches of deflection
- Package of 3 springs sold per unit for efficient stocking
Compatibility
Designed as an OEM-style replacement single loop extension spring for general maintenance and repair applications where a 9/16 inch OD, 16-1/2 inch extension spring is specified.
Installation Notes
Extension springs store mechanical energy under tension and should be installed and removed with appropriate hand tools while wearing eye protection. Always relieve any existing tension in the assembly before removing the old spring. Verify that mounting hooks or pins are rated for the spring load before installation. This type of spring is typically installed by general maintenance technicians or handymen following the equipment manufacturer’s service guidelines.
Technical Specifications
- Outside Diameter: 9/16 inch
- Inside Diameter: 29/64 inch
- Length: 16-1/2 inches
- Wire Diameter: 0.054 inch
- Maximum Safe Load: 9.5 pounds
- Maximum Deflection: 25.2 inches
- Material: Spring Steel
- Finish: Nickel-Plated
- Package Quantity: 3
- Weight: 0.86 pounds
Standard Information
- Brand: PRIME LINE PRODUCTS
- Manufacturer Part Number: SP 9639









