A2 Stainless Steel Serrated Flange Nuts - DIN 6923 Locking Nuts

Serrated hexagon flange nuts manufactured to DIN 6923 (cross-referenced to ISO 4161), combining a standard hex nut and a wide load-spreading flange in a single component. Under the flange, a ring of angled serrations bites into the surface being clamped as the nut is tightened, giving the joint genuine mechanical resistance to loosening under vibration and repeated movement, rather than relying on thread friction alone.

Manufactured from A2 (18-8) stainless steel to property class A2-70, these nuts offer good general-purpose corrosion resistance for indoor, outdoor, and damp environments.

The integral flange effectively builds a flat washer into the nut itself: it spreads the clamping load over a wider bearing area than the nut face alone, protecting the fixed surface and allowing the nut to span slightly oversized or irregular holes.

Compared with fitting a standard hex nut alongside a separate spring or lock washer, this one-piece design combines both jobs in a single fastener: the flange takes on the load-spreading role of a washer, and the serrations provide the locking action normally expected from a spring washer, without a second loose component to source, align, or lose during assembly. That also removes a step from the fitting process, since there is only one part to place and tighten rather than a nut and washer that need to be kept together and orientated correctly.

Key Features

• Serrated hexagon flange nut manufactured to DIN 6923, cross-referenced to ISO 4161
• Integral flange takes the place of a separate flat washer, spreading the clamping load over a wider bearing area
• Angled under-flange serrations bite into the clamped surface for genuine mechanical self-locking under vibration, not just thread friction
• A2 (18-8) stainless steel to property class A2-70 for reliable corrosion resistance indoor, outdoor, and in damp conditions
• Standard DIN 13 metric coarse thread pitch, compatible with ordinary metric bolts, screws, and threaded rod
• Wide flange lets the nut span slightly oversized or irregular clearance holes without the joint working loose
• Six sizes from M4 to M12, each matched to a specific spanner or socket width across flats
• One-piece design – no separate washer to source, align, or lose during assembly

Specification

Installation Guidance

Select the nut size to match the bolt, screw, or threaded rod being used – all sizes share the DIN 13 metric coarse thread pitch given in the specification table above. Fit the nut with the serrated face of the flange against the material being clamped, and tighten with a spanner or socket of the width-across-flats size listed for that size.

A2 stainless is intended for general indoor, outdoor, and damp conditions. Because the locking action is mechanical rather than relying on a thread-locking compound, these nuts can be removed and re-fitted with a spanner or socket in the usual way.

Typical Applications

The combination of vibration-resistant locking, A2 corrosion resistance, and a load-spreading flange makes these nuts a good fit anywhere a plain hex nut risks working loose or a separate washer would otherwise be needed:

• Automotive and motorsport assembly, including exhausts, engine mounts, and suspension components subject to constant vibration
• Machinery guards, motor mounts, and general industrial equipment subject to repeated movement or running vibration
• Outdoor construction, steel fabrication, decking frames, and garden structures, where the A2 stainless build resists the damp and weather that would corrode a plain steel nut
• Panel and sheet-metal assemblies, where the wide flange spreads the clamping load and helps the nut sit securely over a slightly oversized or irregular hole
• General repairs and maintenance on any bolted joint with a history of working loose over time

Order before 2pm Mon–Fri for same-day dispatch from our UK warehouse.