No.1 Screw heads should not be brought to the surface!

Use a flat head

Flat head are more secure than button/pan heads, etc.

They cannot be pinched and turned with pliers!

No.2 Note the shape of the side of the head!

Button head is better than pan head

The closer the angle of the side of the head is to vertical, the easier it is to be pinched and turned by pliers or the like.

It is better to use a button head, which is less likely to be pinched by pliers, than a pan head!

When using a pan head, it is better to embed it in the head for better security!

No.3 When performing washer assembly

Be careful of the raised head!

If a washer or the like is incorporated, the head will be raised and can easily be turned with pliers or the like, so it is recommended that it be embedded.

If you use a screw thread, it is recommended to use an adhesive or nylon type loosening stop on the screw thread.

No.4 Combination of flat head screw + countersunk washer

Increased Security

Since the flat washer and the flat head screw are separate parts, loosening will occur and the flat washer will spin around even if it is clipped with pliers or other tools.

No.5 Use multiple kinds of TRFs!

The use of multiple “TRF” (tamper-resistant fasteners), which are difficult to remove, will increase security to an even greater degree.

The use of unscrewed dummy screws is even more effective!