Drill specification parameters A twist drill for shop use is commonly specified by which basic descriptors?

Introduction / Context:
Specifying a twist drill correctly ensures the right fit in the machine spindle or chuck, appropriate cutting performance for the work material, and accurate hole size. Industry practice uses a set of key descriptors to identify a drill.

Given Data / Assumptions:

• Standard twist drills (jobber length or similar).
• Shop-level specification rather than full engineering standard.
• Focus on essential descriptors.

Concept / Approach:
While full drill specifications may include diameter, overall length, flute length, helix angle, point angle, material/coating, and shank type, the most common quick specification in workshops is by diameter, shank type/size, and material (HSS, carbide, etc.). These three directly affect fit, strength, and suitability.

Step-by-Step Solution:

Verification / Alternative check:
Catalogs and purchasing documents commonly call out diameter, shank type, and material/coating as first-line identifiers, with additional details appended as needed.

Why Other Options Are Wrong:
Lip angle and flute size are important but not the primary shorthand for selection.Length of body and helix angle are secondary; they refine the choice after basics are fixed.“Any one of these” is too loose for procurement; “only diameter” is insufficient.

Common Pitfalls:
Specifying only diameter may lead to incompatible shanks or inadequate tool material for the job. Include core descriptors to avoid delays.

Final Answer:

Shank, material, and diameter