Compression Spring Wire Dia 0.4mm OD 4mm 304 Stainless Steel Vibration Damping

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Compression Spring Wire Dia 0.4mm OD 4mm 304 Stainless Steel Vibration Damping

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By HomeDIYer®

SIZE(CSxODxL): 0.4x4x5mm

QTY(pcs): 10Pcs

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$5.93 USD

Stock:

In stock (500 units), ready to be shipped

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Compression Spring Wire Dia 0.4mm OD 4mm — Reliable Vibration Damping in Tight Spaces

When a mechanism demands precise spring force in a confined bore, an undersized or wrong-grade spring causes premature fatigue, noise, and unplanned downtime. Engineers, makers, and repair technicians who work with miniature assemblies need a compression spring that holds its load rating across thousands of cycles without corroding or losing set. These 304 stainless steel compression springs with 0.4 mm wire diameter and 4 mm outer diameter are engineered for exactly that challenge.

Each spring is cold-wound from 304 stainless steel wire (wire diameter 0.4 mm / 0.016 in, outer diameter 4 mm / 0.157 in) with a closed and ground end finish. Free lengths span 5 mm (0.20 in) to 305 mm (12.01 in) across 20 size options, letting you match the exact travel and rate your design requires. Inner diameter is approximately 3.2 mm (0.126 in), and coil pitch varies by length variant — see variant options for per-size spring rate data.

Typical applications include miniature electronic actuators requiring low-force return springs, precision instrument mechanisms such as pen clips and valve assemblies, robotics and automation end-effectors where corrosion resistance is mandatory, and DIY repair of small appliances, toys, and hobby RC components where a 4 mm OD spring is the standard fit.

🔩 Compatible with bores ≥ 4 mm ID and guide pins ≤ 3.2 mm OD. Suitable for static and dynamic load applications in dry, humid, and mildly corrosive environments.

✅ Key Features of These Compression Springs

🧲304 Stainless Steel Construction

Resists rust, oxidation, and mild chemical exposure — maintains spring force in humid or outdoor environments without surface treatment.

📐Precision Wire Diameter 0.4 mm

Cold-wound to tight tolerances for consistent spring rate and reliable seating in miniature bores and guide assemblies.

📏Wide Length Range: 5 mm to 305 mm

Twenty free-length options in a single listing — select the exact travel you need without sourcing from multiple suppliers.

🔄Vibration Damping Performance

Closed and ground ends distribute load evenly, reducing lateral vibration and noise in high-cycle mechanisms.

📦Flexible Pack Quantities

Available from 1 pc to 100 pcs per order — ideal for prototyping, small-batch production, and maintenance stock.

⚙️Closed & Ground End Finish

Flat ends ensure square seating against spring pockets and retainers, preventing tilt and uneven load distribution.

📐 Technical Specifications — Compression Spring

Material	304 Stainless Steel
Wire Diameter (CS)	0.4 mm (0.016 in)
Outer Diameter (OD)	4 mm (0.157 in)
Inner Diameter (ID)	Approx. 3.2 mm (0.126 in)
Free Length (L)	5 mm – 305 mm (0.20 in – 12.01 in) — see variant options
End Type	Closed and Ground
Spring Rate	See variant options
Surface Finish	Natural (uncoated)
Operating Temperature	-200°C to +300°C (typical for 304 SS)
Pack Quantity	1 / 2 / 3 / 5 / 8 / 10 / 15 / 20 / 25 / 30 / 40 / 50 / 60 / 70 / 80 / 90 / 100 pcs

❓ Frequently Asked Questions

How do I choose the correct free length for my application?

Measure the distance between the two spring seats when the mechanism is at rest (free position). Select a free length equal to or slightly longer than that distance so the spring is lightly preloaded when installed. For dynamic applications, ensure the compressed length at maximum travel does not reach solid height — leave at least 15–20% of free length as working travel margin.

What load can a 0.4 mm wire / 4 mm OD compression spring handle?

With a 0.4 mm wire diameter and 4 mm OD, these springs are designed for light-duty applications typically in the range of 0.05–0.5 N depending on free length and number of active coils. Shorter lengths with fewer coils produce higher rates. For exact spring rate and load data for a specific length variant, contact us to confirm.

Is 304 stainless steel suitable for outdoor or humid environments?

Yes. 304 stainless steel provides good resistance to atmospheric corrosion, moisture, and mild chemical exposure. It is widely used in food-grade, marine-adjacent, and outdoor applications. For highly aggressive environments (salt spray, strong acids), 316 stainless steel would be a stronger choice, but 304 performs reliably in most DIY and light industrial settings.

Will these springs fit a 4 mm bore or guide pin?

The outer diameter is 4 mm, so these springs are designed to fit inside a bore larger than 4 mm (typically ≥ 4.2 mm clearance bore). The inner diameter is approximately 3.2 mm, so a guide pin up to 3.0 mm OD will fit inside the spring with adequate clearance. If your bore is exactly 4 mm, the spring will not fit — select a smaller OD variant.

Can I use these springs for vibration isolation or damping?

Yes. Compression springs with closed and ground ends are commonly used for vibration damping in miniature mechanisms. The flat ends ensure even load distribution and reduce lateral rocking. For best damping performance, select a free length that gives 20–30% compression under the static load of the component being isolated.

How do I select the right quantity for my project?

For prototyping or testing, start with 5–10 pcs to validate fit and spring rate before committing to larger quantities. For small-batch production runs, 50–100 pcs offers better per-unit value. Maintenance and repair applications typically stock 10–20 pcs as replacement inventory. All quantity options are available in a single listing — select your size and quantity above.

Are these springs RoHS compliant?

304 stainless steel is inherently free of the restricted substances covered by RoHS (lead, mercury, cadmium, hexavalent chromium, PBB, PBDE). These springs contain no coatings or platings that would introduce restricted substances. For formal compliance documentation, contact us to confirm.

🛒 Select your size (CS×OD×L) and quantity above, then add to cart.