Bearing Lock Washers (MB Series) are selected when an assembly calls for load distribution and anti-loosening under a bolt or nut. This application guide to the DIN 5406 type covers concrete end-uses, the specification checklist, correct installation, and where an alternative fastener performs better. Stocked across roughly 1 to 12, they cover general to heavy-duty work.
Typical Applications for Bearing Lock Washers (MB Series)
The most common settings where these are specified:
- Bolted structural joints: spreading load over soft or oversized holes and protecting the surface.
- Vibration applications: spring and serrated types that maintain tension under cyclic load.
- Timber & soft materials: large-OD types that prevent pull-through.
- General machine building: fastening covers, brackets, motors and sub-assemblies on production equipment.
- Maintenance & repair (MRO): a stocked size for servicing existing plant where the original fastener spec must be matched.
How to Specify Bearing Lock Washers (MB Series) for Your Application
- Size: Match the nominal size to the mating thread or hole. This product spans 1–12; check the full table below for the exact dimensions of each size.
- Type & OD: Select flat for load spreading, spring/serrated for anti-loosening, or fender/large-OD for soft or oversized holes.
- Environment: For damp, coastal or chemical exposure prefer A4/316 stainless or a suitable coating; indoors, plated steel or A2 is usually sufficient.
- Standard: This product is supplied to DIN 5406. Quoting the standard on your order guarantees interchangeable dimensions between suppliers.
Installation & Assembly Practice
- Place the washer under the rotating element (usually the nut) so tightening does not score the surface.
- Chamfered-hole side of a hardened washer faces the bolt head fillet.
- On serrated-flange hardware, do not add a plain washer — it defeats the serrations.
Common Selection Mistakes with Bearing Lock Washers (MB Series)
- Relying on a spring washer for locking on class 8.8+ joints — at high preload it flattens and adds nothing.
- Choosing an OD too small for soft material, so the head pulls through or embeds.
Where Bearing Lock Washers (MB Series) Are Not the Right Choice
A washer does not replace a locking feature on its own in severe vibration, and a spring washer adds little clamp on high-strength joints.
