What Is a DIN 125 Flat Washer?
DIN 125 Flat Washers
ISO Equivalent: ISO 7089 | Standard Metric Flat Washers
DIN 125 defines the standard metric flat washer used worldwide. These washers distribute load, protect surfaces from fastener damage, and provide a smooth bearing surface for nuts and bolt heads. Available in Form A (without chamfer) and Form B (with chamfer).
Quick Specifications
Type
Flat Washer
Forms
A & B
Size Range
M1.6 – M64
Hardness
100-300 HV
ISO Equivalent
ISO 7089
Dimension Chart
| For Bolt | ID (d₁) | OD (d₂) | Thickness (h) |
|---|---|---|---|
| M3 | 3.2 mm | 7 mm | 0.5 mm |
| M4 | 4.3 mm | 9 mm | 0.8 mm |
| M5 | 5.3 mm | 10 mm | 1.0 mm |
| M6 | 6.4 mm | 12 mm | 1.6 mm |
| M8 | 8.4 mm | 16 mm | 1.6 mm |
| M10 | 10.5 mm | 20 mm | 2.0 mm |
| M12 | 13.0 mm | 24 mm | 2.5 mm |
| M16 | 17.0 mm | 30 mm | 3.0 mm |
| M20 | 21.0 mm | 37 mm | 3.0 mm |
| M24 | 25.0 mm | 44 mm | 4.0 mm |
Material Options
⚙️
Steel – Zinc Plated
Standard carbon steel with clear or yellow zinc. Most economical for indoor applications.
🛡️
A2 Stainless (304)
Excellent corrosion resistance. Match with A2 stainless bolts and nuts.
🌊
A4 Stainless (316)
Marine-grade with molybdenum. For saltwater, chemical, and medical applications.
When to Use Flat Washers
🎯
Load Distribution
🕳️
Oversize Holes
🔧
Surface Protection
📏
Shim/Spacing
💡 DIN 125 vs ISO 7089
Fully interchangeable — Both standards define identical flat washers. ISO 7089 = Form A (no chamfer), ISO 7090 = Form B (with chamfer).