Press tool design — clearance location for blanking During a blanking operation (where the blank is the required product), where is the die–punch clearance provided for correct sizing?

Introduction / Context:
In sheet-metal blanking and piercing, the location of clearance determines which element (blank or hole) matches the tool size. Correct clearance placement ensures dimensional accuracy and acceptable edge quality.

Given Data / Assumptions:

• Blanking: the blank is the desired part; the scrap is the surrounding sheet (skeleton).
• Uniform clearance magnitude appropriate to sheet thickness.
• Standard shearing theory and toolmaking practice.

Concept / Approach:
In blanking, the die opening defines the blank contour and should equal the finished blank size. Therefore, clearance is assigned to the punch (making it slightly smaller), so that the blank sheared from the die opening has accurate dimensions. In piercing, the hole is the desired feature, so the punch should equal the hole size and clearance is provided on the die.

Step-by-Step Solution:
Identify operation: blanking (product is the blank).Set die opening equal to the desired blank size.Provide clearance on the punch to allow shearing and prevent galling.

Verification / Alternative check:
Shop practice and textbooks consistently state: blanking → clearance on punch; piercing → clearance on die.

Why Other Options Are Wrong:

• Die: would size the hole correctly (piercing), not the blank.
• Half-and-half / either: causes tolerance ambiguity and sizing errors for the intended product.

Common Pitfalls:
Mixing up blanking and piercing terminology; always identify whether the product is the blank or the hole.

Final Answer:
punch