Sheet Metalwork — Name the Operation for Straightening a Curved Sheet What is the conventional name of the operation used to straighten and smooth a curved or slightly distorted sheet metal part?

Introduction / Context:After forming or welding, sheet metal parts often need correction to remove waviness and minor curvature while improving surface finish. A specific finishing operation addresses this need using light blows or rolling actions.

Given Data / Assumptions:

• A curved/slightly distorted thin sheet requires flattening and smoothing.
• No major thickness reduction or deep drawing is intended.
• Hand hammers, planishing stakes, or planishing hammers may be used.

Concept / Approach:Planishing is the controlled, repetitive light hammering or rolling of sheet to smooth high spots, relieve local stresses, and straighten minor curvature. It differs from drawing (large plastic flow into a die), coining (severe localized squeezing to imprint), and squeezing (generic compressive operation), focusing instead on finish and slight shape correction.

Step-by-Step Solution:Identify requirement: straighten and smooth, not deeply form.Match operation: planishing uses light blows across the surface to even it out.Reject drawing/coining/flanging, which serve different forming purposes.Conclude operation is planishing.

Verification / Alternative check:Body panel finishing in automotive restoration commonly uses planishing hammers to flatten ripples and waves.

Why Other Options Are Wrong:Drawing: deep cup or box formation; not primarily for straightening.Coining/squeezing: high-pressure imprinting; not a smoothing/straightening finish.Flanging: bending edges; not straightening a whole panel.

Common Pitfalls:Confusing planishing with shot peening; peening induces compressive stress, not sheet straightening and smoothing.

Final Answer:planishing