Situations arise in manufacturing and construction where a protective ring or edge lining is deemed unnecessary for a through-hole. This absence occurs when the material surrounding the aperture is sufficiently robust and resistant to abrasion, preventing damage to cables or wires passing through it. An example includes a thick metal chassis where the drilled opening has been deburred, leaving a smooth, non-abrasive surface.
The omission of this component can streamline the assembly process, reducing both material costs and installation time. Historically, its presence was considered essential for most apertures accommodating wiring. However, advancements in material science and manufacturing techniques have enabled the creation of inherently protective surfaces, thereby negating the need for supplemental protection. This shift has led to more efficient and cost-effective product design.
