Q235 45# 304 316 Matetrial DIN 125 Flat Washer ZP Plain Black Teflon

Plain Washer DIN 125 DIN 9021 

DIN 125 Flat Washer – Technical Description

1. Definition & Standards

The DIN 125 flat washer is a standard metric plain washer used to distribute load, prevent surface damage, and improve fastener stability. It complies with German Industrial Standard (DIN 125) and is equivalent to ISO 7089 for international applications.

2. Key Features

• Shape: Flat, circular with a central hole.

• Material: Typically carbon steel (Grade A or C), stainless steel (A2/A4), or non-ferrous metals.

• Surface Treatment: Plain, zinc-plated, galvanized, or passivated for corrosion resistance.

• Hardness:

  • Grade A (Standard): 140–300 HV (soft, general-purpose).

  • Grade C (Hardened): 300–400 HV (high-strength applications).

  • Stainless Steel (A2/A4): 200–350 HV (corrosion-resistant).

3. Dimensions & Specifications

• Metric Sizes: M1.6 to M100 (covers most standard bolt diameters).

• Thickness & Outer Diameter: Proportional to bolt size (e.g., M10 washer: OD ~20mm, thickness ~2mm).

• Standards: DIN 125 (Germany), ISO 7089 (international), ANSI B18.22.1 (US equivalent).

4. Common Applications

• Load Distribution: Spreads clamping force to protect soft materials (e.g., wood, plastic).

• Surface Protection: Prevents bolt/nut heads from damaging painted or machined surfaces.

• Electrical Isolation: Non-conductive variants (e.g., nylon) used in electronics.

• Structural Bolting: Hardened washers (Grade C) paired with high-strength bolts (Grade 8.8+).

5. Advantages

✔ Cost-Effective – Simple design, mass-produced for bulk use.
✔ Versatile – Compatible with all standard metric bolts.
✔ Corrosion Options – Stainless steel or coated variants for harsh environments.

6. Alternatives & Variants

• DIN 126 – Oversized flat washer for larger bearing surfaces.

• DIN 127 – Spring washer (for anti-loosening).

• ISO 7090 – Parallel-fit washer (precision applications).

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Advantages of DIN 125 Flat Washer

The DIN 125 flat washer is a widely used fastener component with several key benefits, making it essential in mechanical and structural applications. Below are its primary advantages:

1. Load Distribution & Surface Protection

✔ Even Pressure Spreading – Distributes the clamping force of bolts/nuts over a larger area, reducing stress concentration on soft or delicate surfaces (e.g., wood, plastic, or painted metals).
✔ Prevents Damage – Protects assembled surfaces from scratches, indentation, or deformation caused by fastener tightening.

2. Material & Hardness Versatility

✔ Multiple Grades Available –

• Grade A (Soft, 140–300 HV): General-purpose use.

• Grade C (Hardened, 300–400 HV): High-strength applications (e.g., structural bolting).

• Stainless Steel (A2/A4, 200–350 HV): Corrosion-resistant for harsh environments.
  ✔ Custom Coatings – Zinc-plated, galvanized, or passivated options for enhanced durability.

3. Broad Compatibility

✔ Metric Standardization – Fits all standard metric bolts (M1.6 to M100), ensuring interchangeability.
✔ Global Equivalents – Complies with ISO 7089 (international) and ANSI B18.22.1 (US), facilitating global supply chain use.

4. Cost-Effective & Easy to Source

✔ Simple Design – Mass-produced, low-cost, and readily available in bulk.
✔ Reduces Assembly Costs – Eliminates the need for custom-machined spacers or complex solutions.

5. Functional Flexibility

✔ Electrical Isolation – Non-conductive variants (e.g., nylon) for electronics.
✔ Vibration Resistance – When paired with lock washers (e.g., DIN 127), prevents loosening in dynamic loads.

6. Durability & Longevity

✔ Corrosion Resistance – Stainless steel or coated options extend lifespan in outdoor/marine environments.
✔ Reusability – Retains shape and function after disassembly/reassembly.