Conventional Fasteners

Protocase stocks a wide variety of conventional fasteners, and if we don't stock it, we have access to just about any common fastener on a quick-delivery. The most commonly used items are machine screws and hex nuts, which are listed in the table below.

Self-tapping screws vs. machine screw / self-clinching nut combination

In certain situations, a designer has the option of using either

1. a combination of self clinching nut and machine screw, or
2. a self-tapping screw, as shown in the diagram.

We highly recommend option (A), for the following reasons:

• Self tapping screws are subject to stripping
• They interfere with finishes, breaking through powdercoating, and creating potential corrosion problems.
• Inconsistent removal torque --- they can lock in place, and be extremely difficult to remove.

The self tapping screw option is slightly less expensive, but the disadvantages far outweigh the slight savings for most applications. Thus the only place we would ever recommend Option (B) is when searching for cost-engineering solutions on volume orders.