Compression Spring 3mm Wire Diameter 16-21mm OD 20-200mm Length Pressure Spring

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Compression Spring 3mm Wire Diameter 16-21mm OD 20-200mm Length Pressure Spring

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Wire Dia x Outer Dia x Length: 3x16x20mm

Pack Size(Pcs): 1

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$2.92 USD

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In stock (500 units), ready to be shipped

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Compression Spring 3mm Wire — Reliable Pressure Spring for Robotics, Automation & DIY

When a project demands consistent return force and dimensional accuracy, finding the right compression spring can be frustrating. Undersized springs collapse under load; oversized ones won't fit the bore. These 3mm wire diameter compression springs are engineered for engineers, makers, and small-batch manufacturers who need a dependable pressure spring that performs across a wide range of assemblies.

Each spring is wound from 3mm steel wire with an outer diameter (OD) ranging from 16mm to 21mm (approximately 0.63 in to 0.83 in) and a free length spanning 20mm to 200mm (approximately 0.79 in to 7.87 in). The close-wound coil geometry delivers uniform spring rate and consistent end-to-end contact. Available in pack sizes of 1, 3, 5, 10, and 20 pieces to suit both prototyping and production runs.

Typical use cases include compression spring for robotics actuators and gripper mechanisms, pressure spring for industrial jigs and fixtures, and replacement coil spring for 3D printer Z-axis beds, valve assemblies, and mechanical linkages requiring a 3mm wire compression spring with controlled deflection.

⚙️ Compatibility: Suitable for spring bores accepting 16–21mm OD. Verify free length and spring rate against your application before ordering. Multiple sizes available — select your exact Wire Dia × OD × Length above.

✅ Key Features of These Compression Springs

🔩

3mm Wire Diameter

Consistent 3mm wire gauge across all variants ensures uniform coil stiffness and predictable load-deflection behavior for engineering calculations.

📐

Wide Size Range

OD from 16mm to 21mm and free length from 20mm to 200mm — one listing covers dozens of standard compression spring sizes for robotics and automation.

🔄

Close-Wound Coil Geometry

Uniform pitch and closed ends provide stable seating on flat surfaces, reducing lateral buckling during compression cycles.

📦

Flexible Pack Sizes

Order 1, 3, 5, 10, or 20 pieces per variant — ideal for prototyping single units or stocking spares for production maintenance.

⚡

Broad Application Fit

Suited for 3D printer beds, valve springs, mechanical linkages, jig fixtures, and any assembly requiring a reliable 3mm wire pressure spring.

🛡️

Steel Construction

Wound from steel wire for structural integrity under repeated compression cycles — maintains coil shape and return force over extended service life.

📐 Technical Specifications — Compression Spring

Wire Diameter	3mm (0.118 in)
Outer Diameter (OD)	16mm – 21mm (0.63 in – 0.83 in)
Free Length	20mm – 200mm (0.79 in – 7.87 in)
Spring Type	Compression (Pressure Spring)
Coil Style	Close-wound, cylindrical
End Type	Closed ends
Material	Steel wire
Surface Finish	See variant options
Spring Rate	See variant options
Pack Size Options	1 / 3 / 5 / 10 / 20 pieces

❓ Frequently Asked Questions

How do I choose the right OD and length for my application?

Measure the bore or housing inner diameter your spring must fit inside — the spring OD should be slightly smaller than the bore ID to allow free movement. For free length, select a spring that is longer than your required compressed length so it maintains positive force at full compression. Use the Wire Dia × OD × Length option selector above to find your exact size.

What load can a 3mm wire compression spring handle?

Load capacity depends on the specific OD, free length, and material grade. A 3mm wire diameter spring typically handles moderate loads suitable for robotics actuators, 3D printer beds, and light industrial fixtures. For precise load and deflection data, contact us to confirm the spring rate for your selected variant.

Are these springs corrosion-resistant?

These springs are wound from steel wire. For corrosion-sensitive environments such as outdoor use or exposure to moisture, consider applying a protective coating or contact us to confirm the surface finish of your selected variant. For dry indoor applications — robotics, 3D printers, jigs — standard steel construction performs reliably.

Will these compression springs fit standard spring bores?

The OD range of 16mm–21mm covers many standard metric bore sizes. Verify the bore ID of your housing is at least 0.5–1mm larger than the spring OD to ensure free travel. The closed-end coil design seats flat on standard spring pockets without additional hardware.

Can I use these as replacement springs for 3D printers or CNC machines?

Yes. The 3mm wire compression spring range is commonly used as bed-leveling springs for FDM 3D printers and as return springs in CNC axis assemblies. Select the OD and free length that matches your original spring specification. Pack sizes of 5 or 10 are popular for keeping spares on hand.

What is the difference between the various length options (20mm to 200mm)?

Free length determines the uncompressed height of the spring and directly affects the working travel (stroke) available. Shorter springs (20–50mm) suit compact assemblies with limited travel; longer springs (100–200mm) are used where greater deflection range or softer spring rate is needed. Match the free length to your assembly's available spring pocket depth plus required stroke.

How many pieces should I order for a prototype vs. production run?

For prototyping or testing a single assembly, the 1-piece or 3-piece pack is ideal. For small production batches or to maintain a spare inventory, the 5-piece or 10-piece pack offers better value per unit. The 20-piece pack suits higher-volume production or maintenance stock for machines with multiple spring positions.

🛒 Select your Wire Dia × OD × Length and Pack Size above, then add to cart.