Sheet-metal operations — definition of lancing In pressworking terminology, “lancing” refers to which operation on sheet metal?

Introduction / Context:Press shop vocabulary distinguishes many operations that look similar but serve very different design goals. Lancing is one such operation used to create tabs, louvers, or ventilation slots without producing a separate slug.

Given Data / Assumptions:

• Work material is thin sheet.
• Tooling uses a punch and die but deliberately avoids full shearing through the stock.
• Objective is to create an opening or projection by partial cut plus bend.

Concept / Approach:In lancing, the punch shears part of the perimeter while the remaining material acts as a hinge or bridge. The subsequent downward travel or a secondary station bends the cut tongue out of plane, forming a tab, louver, or vent. No slug is produced, which reduces handling and can speed production. This is distinct from blanking (complete perimeter cut producing a slug/blank), notching (edge removal), slitting (long straight cuts), or pure bending.

Step-by-Step Solution:Define the action: partial shear followed by immediate or subsequent bending.Identify the outcome: a raised feature or opening without separate scrap pieces.Match to the listed options: option (c) captures this definition precisely.

Verification / Alternative check:Die design manuals list lancing as a combined shearing and forming operation, illustrating louvers/tabs made without producing loose slugs.

Why Other Options Are Wrong:

• Slitting: full-length straight shear, no bending.
• Notching/trim: removes metal at the edge, not a hinged tab.
• Curved-axis bending: pure forming, no shearing step.
• Blanking: complete perimeter shearing producing a separate blank.

Common Pitfalls:Confusing lancing with piercing; piercing creates a hole and a scrap slug, while lancing leaves material attached and forms it.

Final Answer:Cutting a sheet only partway through its length and then bending the cut portion to form a tab or vent