Screws and fasteners.

In knife making, different types of screws are generally used to fasten components together, such as handle inserts, pocket clips and various parts of the mechanism. Common screws include those with flat heads, domed heads and countersunk heads. Here's an overview of these screw types:

Flat-head screws (flat-head screws, pan-head screws):

• These screws have a flat head that is slightly raised above the surface of the material once the screw is tightened.
• They are often used when the screw needs to be more discreet and flush with the surface of the material.
• Flat-head screws are commonly used in knives where aesthetics are important, as they offer a smoother, more uniform finish.

Round-head screws:

• Round-head screws have a rounded head that rises above the surface of the material once the screw is tightened.
• They offer a better grip when screwing, and are often used where pull-out strength is required.
• In some knives, domed-head screws may be used to add a design element or for functional reasons, e.g. to facilitate blade opening.

Countersunk head screws (conical head screws):

• countersunk screws have a tapered head that blends completely into the material once the screw has been tightened.
• They offer a smooth, flat finish, making them ideal for applications where aesthetics are paramount.
• In knives, countersunk screws can be used to secure handle inserts while ensuring a smooth, pleasant-to-the-touch surface.

M2 and M3 screws refer to different standard screw sizes. The designation "M" stands for "metric", and the number following indicates the nominal thread diameter in millimeters.

M2 screws :

• Nominal thread diameter: 2 mm
• Smaller and thinner than M3 screws.
• Used in cutters where space is limited or where more discreet fixings are required.

M3 screws :

• Nominal thread diameter: 3 mm
• Larger and stronger than M2 screws.
• Used where greater strength and robustness are required, e.g. for fastening heavier components or for applications requiring a more solid fixing.

In short, flat-head, domed and countersunk screws offer different aesthetic and functional options in knife manufacturing. The choice between M2 and M3 screws will depend on knife specifications, materials used and strength and performance requirements.