Home » DIN 128A Lock Washer Spring – A2 Stainless

DIN 128A Lock Washer Spring – A2 Stainless

DIN 128A Curved Spring Lock Washer — A2 Stainless Steel (SUS304), Whitened & Passivated

FULLERKREG DIN 128A curved spring lock washers are manufactured to DIN 128 Type A standard in A2 stainless steel (SUS304 / 1.4301 / 0Cr18Ni9) with a whitened and passivated surface finish. DIN 128 Type A is a curved (single-coil) spring washer that generates axial spring force through its curved profile, providing anti-loosening performance in bolted assemblies. Unlike the helical split design of DIN 127, the curved profile of DIN 128A distributes load more evenly and is particularly suited for use with cheese head screws (DIN 84) and pan head screws. A2 stainless steel provides excellent general corrosion resistance, non-magnetic properties, and food-safe compliance.

Product Highlights

  • Standard: DIN 128 Type A (Curved Spring Lock Washer)
  • Material: A2 Stainless Steel (SUS304 / 1.4301 / 0Cr18Ni9)
  • Surface Treatment: Whitened & Passivated
  • Size Range: M2 – M36
  • Profile: Type A — Curved (single-coil, not helical split)
  • Function: Axial spring force via curved profile — anti-loosening, load distribution
  • Non-magnetic, non-sparking
  • RoHS & REACH Compliant

Dimensional Specifications — DIN 128 Type A (Curved), A2 Stainless

All dimensions in millimeters (mm). Per DIN 128 Type A.

Nominal Size For Bolt d1 min d2 max h min h max s (thickness) b (width)
2 M2 2.1 4.4 0.70 1.10 0.6 0.9
2.3 M2.3 2.4 4.9 0.90 1.10 0.6 0.9
2.5 M2.5 2.6 5.1 0.90 1.10 0.6 1.0
2.6 M2.6 2.7 5.2 0.90 1.10 0.6 1.0
3 M3 3.1 6.2 1.10 1.30 0.7 1.3
3.5 M3.5 3.6 6.7 1.20 1.30 0.7 1.3
4 M4 4.1 7.6 1.20 1.40 0.8 1.5
5 M5 5.1 9.2 1.50 1.70 1.0 1.8
6 M6 6.1 11.8 2.00 2.20 1.3 2.5
8 M8 8.1 14.8 2.45 2.75 1.6 3.0
10 M10 10.2 18.1 2.85 3.35 1.8 3.5
12 M12 12.2 21.1 3.35 3.65 2.1 4.0
14 M14 14.2 24.1 3.90 4.30 2.4 4.5
16 M16 16.2 27.4 4.50 5.10 2.8 5.0
18 M18 18.2 26.4 4.50 5.10 2.8 5.0
20 M20 20.2 33.6 5.10 5.90 3.2 6.0
22 M22 22.5 35.9 5.10 5.90 3.2 6.0
24 M24 24.5 40.0 6.50 7.50 4.0 7.0
27 M27 27.5 43.0 6.50 7.50 4.0 7.0
30 M30 30.5 48.2 9.50 10.50 5.0 8.0
36 M36 36.5 58.2 10.30 11.30 6.0 10.0

All dimensions in mm per DIN 128 Type A. s = material thickness; b = ring width; h = free height (curved profile height). Please verify with your engineering team for critical applications.

DIN 128 Type A vs. Type B — Key Differences

Feature DIN 128 Type A (Curved) DIN 128 Type B (Wavy)
Profile Single curved arc Wavy / corrugated (multiple waves)
Spring action Axial spring via single curve Axial spring via multiple waves
Load distribution Even, smooth bearing surface Multi-point contact
Typical use Cheese head & pan head screws General bolted assemblies
Size range (DIN 128) M2 – M36 M2 – M36

DIN 128A vs. DIN 127B — Key Differences

Feature DIN 128 Type A (Curved) DIN 127 Type B (Helical Split)
Profile Curved single-coil ring Helical split ring
Anti-loosening mechanism Axial spring force only Spring force + bite-in effect
Load distribution Smooth, even bearing surface Sharp edges bite into surfaces
Surface damage Minimal Marks bearing surface
Typical use Soft materials, coated surfaces, cheese head screws General heavy-duty assemblies

Material & Mechanical Properties — A2 Stainless Steel (SUS304)

Property Value
Material Grade A2 / SUS304 / 1.4301 / 0Cr18Ni9
Cr Content 17.5 – 19.5%
Ni Content 8.0 – 10.5%
Surface Treatment Whitened & Passivated
Magnetic Non-magnetic (austenitic)
Operating Temperature -196°C to +300°C
Corrosion Resistance Excellent — atmospheric, fresh water, mild chemicals
RoHS / REACH Compliant

How DIN 128A Curved Spring Washers Work

  • Curved profile: The washer is formed into a curved arc. When compressed under bolt load, it acts as a spring, maintaining axial clamping force as the joint settles
  • Anti-loosening: The spring-back force compensates for relaxation and embedding losses, keeping the bolt under tension
  • Even load distribution: The smooth curved surface distributes load evenly without marking or damaging the bearing surface — ideal for soft materials and coated surfaces
  • Designed for cheese head screws: The reduced outer diameter and curved profile are optimized for use with DIN 84 cheese head and DIN 7985 pan head screws

Application Scenarios

  • Cheese head screw assemblies (DIN 84) — optimized OD fits within screw head recess
  • Pan head screw assemblies (DIN 7985) — smooth curved profile suits pan head applications
  • Food & beverage processing equipment — A2 stainless, food-safe, easy to clean
  • Medical & pharmaceutical equipment — non-magnetic, corrosion-free
  • Electronics & precision instruments — non-magnetic, no surface damage
  • Outdoor & architectural hardware — excellent atmospheric corrosion resistance
  • Chemical & water treatment equipment — resistance to mild chemicals and fresh water

Product Photo Gallery

FULLERKREG DIN 128A Curved Spring Lock Washer, A2 Stainless Steel:

[ Photo 1 ] [ Photo 2 ] [ Photo 3 ] [ Photo 4 ]

Packaging & Supply

Size Standard Pack (pcs) Bulk Carton (pcs)
M3 200 10,000
M4 200 5,000
M5 100 3,000
M6 100 2,000
M8 50 1,000
M10 50 500
M12 25 500
M16 25 200
M20 10 100
M24 10 50

Custom packaging and labeling available for OEM / wholesale orders. Contact FULLERKREG for bulk pricing.

Why Choose FULLERKREG?

  • 🏭 Direct manufacturer — factory in China, no middlemen
  • 📐 Strict DIN dimensional control — 100% inspection on critical dimensions
  • 🌍 Global export experience — serving distributors in Europe, North America, Southeast Asia
  • 📦 Flexible MOQ — small trial orders and large bulk shipments both welcome
  • 📋 Full documentation — material certs, RoHS declarations, test reports available
  • ⚡ Fast lead times — standard sizes in stock, ready to ship

Frequently Asked Questions

Q: What is DIN 128 Type A?
A: DIN 128 Type A is a curved spring lock washer standard. The washer is formed into a single curved arc (not helical split like DIN 127). When compressed, it acts as a spring to maintain bolt tension and resist loosening. Type A is curved; Type B is wavy (corrugated).

Q: What is the difference between DIN 128A and DIN 127B?
A: DIN 127B is a helical split ring that uses both spring force and sharp edge bite-in to resist loosening. DIN 128A uses only axial spring force via its curved profile, with no sharp edges — making it suitable for soft materials, coated surfaces, and applications where surface marking must be avoided.

Q: Which screw types is DIN 128A designed for?
A: DIN 128A is specifically designed for use with cheese head screws (DIN 84 / ISO 1207) and pan head screws (DIN 7985 / ISO 7045). The reduced outer diameter fits within the head recess of these screw types.

Q: Is A2 stainless steel food-safe?
A: Yes. A2 (SUS304) stainless steel is widely used in food processing and pharmaceutical equipment. It is non-toxic, easy to clean, and resistant to most food-contact environments.

Q: Are all sizes in stock?
A: Standard sizes M2–M36 are typically in stock. Please contact FULLERKREG to confirm availability for your specific size and quantity.

Q: Do you provide material test certificates?
A: Yes. Mill certificates, chemical composition reports, and dimensional inspection reports are available upon request.

FULLERKREG Fasteners — Precision DIN Standard Fasteners, Direct from Manufacturer.
For wholesale inquiries, technical questions, or custom orders, please contact our sales team.

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