Extension Springs

Assorted Extension Springs
Assorted Extension Springs

The premium quality custom extension springs we produce at Jackson Spring Mfg. Co. Inc. are manufactured using SAE and ASTM grade stainless steel, copper, and alloy steel wire between 0.020” and 0.163” in diameter. Spring hooks can be formed in a number of shapes including extended hooks, side hooks, center hooks, and other custom configurations. We operate a wide array of spring manufacturing systems that allow us to produce a range of custom springs in many types and sizes with right or left helix directions. Multiple surface treatments such as zinc, black oxide, color coatings, and grinding can be applied to meet corrosion resistance and aesthetic requirements.

Our team is dedicated to providing the best customer service in the industry and is capable of economically producing precision springs to customer prints. We can efficiently manufacture a range of part volumes and offer JIT delivery to ensure that customers receive parts when they are needed without incurring excess inventory costs. Specific lead times are quoted on a job by job basis, with typical turnaround times averaging 3 to 4 weeks. For additional information about our custom extension spring manufacturing capability, see the table below, or contact us directly.

Extension Spring Highlights

Spring End Configurations
Combination Hooks
Custom Shaped Hooks
Extended Hooks
Hooks on Center
Side Hooks
Spring Materials
Stainless Steel
Alloy Steel
Spring Material Grades
Carbon Steel:
  • ASTM A229 (Oil Tempered MB Grade)
  • SAE 1080 (Oil Tempered GB Grade)
  • ASTM A227 (Hard- Drawn MB grade)
  • ASTM A228 (Music Wire)
  • SAE 1074 (Blue Tempered or Annealed)
  • SAE 1064 (Blue Tempered or Annealed)
  • SAE 1070 (Blue Tempered or Annealed)
  • SAE 1095 (Blue Tempered)

Alloy Steel:

  • ASTM A231 (Chromium Vanadium)
  • ASTM A401 (Chromium Silicon)
  • ASTM A313 ( Stainless )
  • SAE 51414 (Stainless)
  • SAE 51420 (Stainless)
  • SAE 51431 (Stainless)


  • ASTM B 134 (Spring Base)
  • ASTM B 159 (Phosphor Bronze)
  • ASTM B 197 ((Beryllium copper)
Surface Treatment
Black Oxide
Cleaned & Oiled
Zinc Plating
CNC Machinery
Compression Spring Coiler
Mechanical Coiler
CNC Coiler
CNC Multi radical Formers
Additional Services
CAD Design
Color Coating
Vision System
Optical Comparison
Various Load Testing
Helix Direction
Wire diameter
Min: 0.020”
Max: 0.163”
Production Volume
Specialty Production Shop
Long Runs
High Volume
Typical Lead Time
3-4 Weeks Job to Job Basis
Rush Services Available
Emergency Services Available
JIT Deliveries

Additional Information

Industry Focus
Fluid Sealing
Fire Arms
Industry Standards
CASMI - Chicago Association of Spring Manufacturers, Inc.
SMI - Spring Manufacturers Institute
IATF 16949:2016 & ISO 9001:2015 - International Organization for Standardization

ITAR Registered 

Lights Out Manufacturing
File Formats
IGES - Initial Graphics Exchange Specification, ANSI file format.
PDF - Portable Document Format
STEP - Standard for the Exchange of Product Model Data