Compact. Powerful. Effective.

What they are: Hydra Spring® units are precision hydraulic devices that provide a remarkably high spring force from a very small package. The compact size makes them ideal where space is at a premium. Imagine having 600% more force than coil springs of similar dimensions. Requiring just a small space "envelope" within a die or mold allows designers to place spring force where it is needed. The cost savings in die size, material saved, and machining time saved when making a die or mold can be truly significant.

Applications: Hydra Spring units may be used for the stripping, lifting, or releasing functions within die sets or molds. Typically, other applications for Hydra Springs include conventional die sets where high stripping pressures are required and space is at a premium. They may be used as individual components in larger tools or in conjunction with (external to) a die. Other applications include plastic injection dies, heavy perforating equipment, cable-tensioning devices, recoil mechanisms … any application requiring powerful spring forces, instant action and compact size.

How they work: These precision hydraulic assemblies use the low compressibility of special hydraulic fluids to produce the remarkably high spring force. When the action of the press or mold machine forces the piston down into the Hydra Spring, the oil compresses and pushes back against the piston providing the high spring force. The maximum force developed is determined by unit design and the type and amount of hydraulic fluid used. Hydra Springs are delivered with various factory set preloads, and their "instant action" allows for consistent, reliable spring rates along the entire curve of the working stroke. Seven models are available with maximum force that ranges from 2200 up to 8500 pounds.

Hydra Springs develop tremendous spring forces within a very small space.

Click here to download a brochure for Hydra Springs.


Part # Curve Letter Preload (Pounds) Working Stroke (Inches) Maximum Force (Pounds) Spring Rate (Pounds/Inch)  Unit Diameter (Inches)  Unit Length (Inches) * Thread Size
HS-38K11
A 1,650 1/4 3,800 8,600 1-3/8 3-1/4  3/4-16 NF
B 1,500 1/4 2,850 5,400 1-3/8 3-1/4  3/4-16 NF
C 1,000 1/4 2,200 4,800 1-3/8 3-1/4  3/4-16 NF
D 2,750 3/32 3,800 11,200 1-3/8 3-1/4  3/4-16 NF
HS-38K14
A 500 3/4 3,800 4,400 1-3/4 3-3/4  3/4-16 NF
B 1,000 5/8 3,800 4,500 1-3/4 3-3/4 3/4-16 NF
C 500 1/2 3,800 6,600 1-3/4 3-3/4  3/4-16 NF
D 1,000 7/16 3,800 11,200 1-3/4 3-3/4  3/4-16 NF
HS-38K18
A 500 1-1/2 3,800 2,200 2-1/4 5  3/4-16 NF
B 1,000 1-1/16 3,800 2,600 2-1/4 5  3/4-16 NF
C 500 15/16 3,800 3,500 2-1/4 5  3/4-16 NF
D 1,000 3/4 3,800 3,700 2-1/4 5  3/4-16 NF
HS-60K14
A 500 1/2 6,000 11,000 1-3/4 3-1/2  3/4-16 NF
B 1,900 5/16 6,000 13,100 1-3/4 3-1/2  3/4-16 NF
C 500 3/8 6,000 14,700 1-3/4 3-1/2  3/4-16 NF
HS-60K18
A 500 1 6,000 5,500 2-1/4 4-1/2  3/4-16 NF
B 1,800 11/16 6,000 6,100 2-1/4 4-1/2  3/4-16 NF
C 500 3/4 6,000 7,300 2-1/4 4-1/2  3/4-16 NF
HS-85K14
A 500 3/8 8,500 21,300 1-3/4 3-3/8  3/4-16 NF
B 2,800 1/4 8,500 23,000 1-3/4 3-3/8  3/4-16 NF
C 500 1/4 8,500 32,000 1-3/4 3-3/8  3/4-16 NF
HS-85K18
A 500 3/4 8,500 10,700 2-1/4 4-1/4  3/4-16 NF
B 2,500 1/2 8,500 12,000 2-1/4 4-1/4  3/4-16 NF
C 500 1/2 8,500 16,000 2-1/4 4-1/4  3/4-16 NF
* This length measurement does not include the 3/4-16 NF 3/4" long mounting stud (see drawing below).