Flat washers
Flat washers distribute clamp load and protect painted or soft surfaces. Match inner diameter to the bolt thread.
Spring lock washers
Spring lock washers add friction against loosening in light vibration. They are not a substitute for proper torque or locking methods on safety-critical joints.
Common stack
Bolt head → spring washer → flat washer → joint → flat washer → nut
Confirm the stack with your drawing before production.
FAQ
Q: Do I always need both?
A: No. Many static indoor assemblies use flat washers only.
Q: Stainless with stainless — galling risk?
A: For high-cycle assembly, ask about lubrication or anti-seize guidance on the RFQ.