Advantages
PSM Flat nuts are one piece, heat treated, self-locking spring steel fasteners which provide the most inexpensive means of threaded fastening usually without the need for a spanner. They replace conventional threaded nuts and lock washers in low torque applications.
- One piece application
- No spanner usually
- required
- Vibration proof
- Self locking
- Non-paint clogging
- Reusable
MATERIAL
CS60, CS70 carbon steel,
austempered
WHEN SPECIFYING, PLEASE STATE:
- Quantity
- Prefix (CBFN)
- Part No.
- Finish code (e.g. e.g. 2500 CBFN-0410-0)
METHOD OF ASSEMBLY:
Hold fastener over the mounting hole in exactly the same manner as conventional nut and tighten screw up to recommended torque.
Characteristics & Key Features
Flat nuts are made from spring steel grades (like CS60, CS70) with heat treatment to maintain resilience and locking behavior.
They combine nut and locking function in one piece—so you typically don’t need separate lock washers.
Vibration-proof by design, the flat nut resists loosening under cyclic loads.
They are non-clogging with paint or coatings, meaning surface finishes remain clean.
They are reusable, allowing multiple assembly cycles in many applications.
Their simple form factor makes them an economical option for moderate load applications without requiring a specialized tool.
Material Selection & Specification Guidelines
- Specify the correct spring steel grade and finish for the intended environment (corrosion, wear, temperature).
- Provide the flat nut prefix (e.g. CBFN) and part numbering format to match dimensions.
- Indicate finish codes (e.g. 2500 CBFN-0410-0) when ordering to ensure consistency and compatibility.
- When designing mating components, ensure the flat nut’s locking features (e.g. helical thread impression, earthing barbs) properly engage the screw and substrate.
Feature Code
- Helical thread impression
- Earthing barbs
Flat Nuts Dimensions
Installation & Use Instructions
- Position the flat nut over the mounting hole just like a conventional nut.
- Place the screw through the mating parts into the flat nut.
- Tighten up to the recommended torque—this engages the locking feature without overstraining the nut.
- Ensure the helix impressions fully seat into the screw threads for locking action.