Compression Spring 3mm Wire Diameter 21-27 mm Outer Diameter Small Spring Steel

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Compression Spring 3mm Wire Diameter 21-27 mm Outer Diameter Small Spring Steel

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Wire diameter x Outer diameter x Length: 3x21x30mm

Quantity（Pcs): 5

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$20.74 USD

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In stock (500 units), ready to be shipped

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Compression Spring 3mm Wire Diameter — Reliable Return Force for Tight Spaces

When a mechanism fails because a spring loses tension or snaps under repeated cycling, the culprit is often an undersized or wrong-material spring. Makers, machinists, and workshop technicians who need a dependable small compression spring in a compact outer diameter will find this range covers the most common fitment scenarios without custom ordering.

Each spring is formed from spring steel wire with a nominal wire diameter of 3 mm (0.118 in). The outer diameter spans 21–27 mm (0.827–1.063 in) across the available variants, and free lengths range from 20 mm to 100 mm (0.79–3.94 in). Springs are sold in packs of 5 or 10 pieces, making it straightforward to stock spares or fulfil small-batch production runs.

Typical applications include mechanical return mechanisms in jigs and fixtures, valve and plunger assemblies requiring a 21–27 mm bore fit, DIY automation projects using 3 mm wire springs, and replacement springs in hand tools, latches, and industrial equipment where a small-diameter compression spring is specified.

🔧 Compatible with standard spring seats and bores sized for 21–27 mm outer diameter and 3 mm wire. Verify free length and spring rate against your application before ordering.

✅ Key Features of These Compression Springs

🔩3 mm Wire Diameter

Consistent 3 mm wire cross-section delivers predictable spring rate and load capacity across all size variants.

📐Wide OD Range: 21–27 mm

Seven outer diameter steps (21, 22, 23, 24, 25, 26, 27 mm) let you match the exact bore or seat in your assembly.

📏Free Lengths 20–100 mm

Multiple free-length options from 20 mm to 100 mm (0.79–3.94 in) cover short-stroke and longer-travel applications.

⚙️Spring Steel Construction

Formed from spring steel wire for resilient elastic deformation and resistance to fatigue under repeated compression cycles.

📦Pack Quantities: 5 or 10 Pcs

Choose a 5-piece pack for prototyping or a 10-piece pack for production runs and maintenance stock.

🔄Closed & Ground Ends (Typical)

Standard closed ends provide flat seating surfaces for stable load transfer in spring seats and plunger housings.

📐 Technical Specifications — Compression Spring

Wire Diameter	3 mm (0.118 in)
Outer Diameter	21 mm / 22 mm / 23 mm / 24 mm / 25 mm / 26 mm / 27 mm — See variant options
Free Length	20–100 mm (0.79–3.94 in) — See variant options
Material	Spring Steel
End Type	Closed (typical)
Spring Rate	See variant options
Surface Finish	See variant options
Pack Quantity	5 pcs or 10 pcs — See variant options
Application	Compression / Return Force

❓ Frequently Asked Questions

How do I choose the right outer diameter for my application?

Measure the bore or spring seat in your assembly. The spring's outer diameter should be slightly smaller than the bore so it can compress freely without binding. For a 22 mm bore, a 21 mm OD spring typically provides adequate clearance. Select the variant whose OD matches your seat diameter minus 0.5–1 mm of clearance.

How do I select the correct free length?

The free length should be longer than your required working length. Determine the compressed length at maximum deflection and the desired preload at installed length, then choose a free length that gives you the correct spring travel. Available free lengths run from 20 mm to 100 mm in this range.

What load can a 3 mm wire compression spring handle?

Load capacity depends on wire diameter, outer diameter, free length, and number of active coils. A 3 mm wire spring in this OD range is suited to light-to-medium duty applications. For precise load requirements, contact us to confirm the spring rate and solid height for your chosen variant.

Are these springs corrosion-resistant?

These springs are made from spring steel, which offers good mechanical properties but limited inherent corrosion resistance. For humid or outdoor environments, consider applying a light coating of oil or grease, or contact us to confirm if a surface-treated variant is available for your size.

Can I use these springs in automated machinery or jigs?

Yes. Spring steel compression springs in this wire and OD range are commonly used in jig return mechanisms, plunger assemblies, and light automation fixtures. Verify the spring rate and fatigue life against your cycle count and load requirements before committing to a production run.

Why should I buy a 10-piece pack instead of 5?

A 10-piece pack reduces the per-unit cost and ensures you have spares on hand for maintenance or prototyping iterations. If you are running a small production batch or need to stock a maintenance kit, the 10-piece option offers better value and fewer reorder interruptions.

How do I confirm the spring fits before I order?

Check three dimensions: wire diameter (3 mm), outer diameter (21–27 mm depending on variant), and free length (20–100 mm depending on variant). Cross-reference these against your assembly drawing or measure the existing spring with calipers. If you are unsure, contact us to confirm compatibility before ordering.

🛒 Select your Wire diameter × Outer diameter × Length and Quantity above, then add to cart.

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These o rings are a great for my ear tunnels

These o rings are a great for my ear tunnels, always loosing one here and there, I always have a new ones in the drawer. Being silicone, don't have any reactions compared to standard rubber ones I purchased at hardware stores, plus much less expensive. Purchased 16mm I'd to use on 19mm tunnels, and stay on great, might be able to get away with 17mm rings, but really happy with my choice.

Will never order from these folks again

I waited a long time and that’s all I received was the eyebolt with no threaded rod attached to it

Perfect they are really made well and I used them for my car

Perfect they are really made well and I used them for my car. The only thing I had a great for us. It took three weeks to get here. So shipping was slow.

did not include wing nuts

Hi Scott, thank you for your feedback. We're sorry for any inconvenience caused. Please get in touch with us directly, and we'll assist you. Thanks for shopping with HomeDIYer!

Haven't received the order yet! It's been over

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Compression Spring 3mm Wire Diameter 21-27 mm Outer Diameter Small Spring Steel

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Description

Compression Spring 3mm Wire Diameter — Reliable Return Force for Tight Spaces

✅ Key Features of These Compression Springs

📐 Technical Specifications — Compression Spring

❓ Frequently Asked Questions

Compression Spring 3mm Wire Diameter 21-27 mm Outer Diameter Small Spring Steel

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