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129CS - 8.50 Inch High Carbon Steel Extension Springs

The 129CS is a regular extension spring manufactured by Century Spring. It is made from High Carbon steel and has a zinc finish. This spring has a wire diameter of 0.091 inches, an outer diameter of 0.625 inches, and a free length of 8.5 inches. It has an initial tension of 9 Pound and a maximum deflection of 3.8 inches. The 129CS has a spring rate of 7.7 inches per pound and a maximum load of 39 Pound Force. It features machine hooks on both ends. This regular extension spring is suitable for various applications.

At Century Spring, we pride ourselves on our fast shipping and extensive stock inventory. Our products, including the 129CS, are proudly made in the United States. With our efficient shipping process and large supply, we ensure that customers can rely on us to quickly deliver the springs they need for their projects.

Unit System
View Spec Sheet
Specs (in standard)
Label Value
Brand Century Spring
Ends Machine Hook
Finish Zinc
Initial Tension 9 lb
Length 8.5 in
Material High Carbon Steel
Outside Diameter 0.625 in
Part Type Standard
Rate 7.7 lbs/in
SKU 129CS
Sugg Max Deflection 3.8 in
Sugg Max Load 39 lbf
Wind Direction Left
Wire Diameter 0.091 in
Specs (in metric)
Label Value
Brand Century Spring
Ends Machine Hook
Finish Zinc
Initial Tension 4.08 kg
Length 215.9 mm
Material High Carbon Steel
Outside Diameter 15.88 mm
Part Type Standard
Rate 1.35 N/mm
SKU 129CS
Sugg Max Deflection 96.52 mm
Sugg Max Load 173.47 N
Wind Direction Left
Wire Diameter 2.31 mm
Inventory Status
In-stock
Estimated Lead Time
In-stock parts: usually ships in 12-24 hours
Quantity Price
1 - 49 $9.20
50 - 149 $8.74
150 - 299 $8.28
300 - 499 $7.82
500 - 749 $6.90
750 - 999 $5.98
1000+ Call for price