Machine capacity terminology: A “15 mm drilling machine” can drill a hole of what capacity?

Introduction / Context:
Manufacturers describe drill presses by a capacity number (e.g., 10 mm, 15 mm, 25 mm). Understanding this nomenclature helps select the correct machine for a job.

Given Data / Assumptions:

• Capacity refers to mild steel drilling capability under standard conditions.
• Tooling and feeds are appropriate for the rating.

Concept / Approach:
The capacity designation indicates the largest hole diameter the machine is designed to drill in a typical material (commonly mild steel) with standard tooling, within safe power and rigidity limits.

Step-by-Step Solution:

Verification / Alternative check:
Spec sheets show motor power, spindle taper, and “maximum drilling diameter” matching the capacity value.

Why Other Options Are Wrong:

• “In 15 mm thick plates” confuses thickness with diameter capacity.
• “15 mm^2 area” is unrelated to drilling capacity terminology.
• “None of these” is incorrect since the standard meaning is well defined.

Common Pitfalls:
Ignoring that real achievable diameter depends on work material; hard alloys may require derating even if the nominal capacity is 15 mm.

Final Answer:
Maximum diameter 15 mm