Spring washers are designed to act as an axial spring, flexing elastically under clamping loads to absorb vibration, accommodate thermal expansion, or provide a locking mechanism.
These standard locking washers are split at one point and twisted into a helix. When compressed, they act like a single-turn coil spring to maintain assembly tension.
They are categorized by the cross-sectional geometry of their wire or ring profile.
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Cross-Section
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Engineering Description & Function
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Common Standard
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Square Section
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Features a perfectly square cross-section profile. Designed with a narrower outer diameter specifically to seat flush within the counterbores of socket head cap screws.
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DIN 7980 / BS 4464 Type A
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Rectangular Section
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Features a wider, flattened rectangular profile. Provides a broader bearing footprint, ideal for typical hexagon-head bolts and nut assemblies.
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DIN 127 Type B / BS 1802
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Material Configurations and Properties
The choice of material dictates a spring washer's elasticity, fatigue lifespan, and maximum load capacity:
- Carbon Spring Steel The choice for standard mechanical assemblies. It delivers maximum tensile strength and excellent spring-back resilience. It must be treated with protective coatings—such as Bright Zinc Plating (BZP) or Phosphating—to mitigate rapid rust formation.
- A2 (304) Stainless Steel: Highly resistant to fresh water, atmospheric humidity, and food handling environments. It possesses lower ultimate mechanical hardness than carbon spring steel but eliminates corrosion pitting risks.
- A4 (316) Marine Stainless Steel: Heavily enriched with molybdenum to provide robust protection against harsh saltwater environments and aggressive chemical processing exposure.
Phosphor Bronze / Silicon Bronze: Non-ferrous, non-magnetic alloys offering highly stable spring properties coupled with excellent electrical conductivity. Frequently integrated directly into marine switchgear and electrical terminal infrastructure to prevent galvanic corrosion
