Hot piercing — typical applications Is hot piercing extensively used for making bolts and nuts in industrial practice?

Introduction / Context:
Hot piercing is a bulk-deformation process where a solid billet is pierced to create a hollow, often as a precursor to seamless tubes (Mannesmann process). The question challenges a common misconception by asking whether hot piercing is widely used to produce bolts and nuts.

Given Data / Assumptions:

• Bolts and nuts are standard fasteners.
• Typical manufacturing routes for fasteners include heading, thread rolling, machining, and forging.
• Hot piercing produces hollows/tubes rather than solid shanks and hexagonal nuts directly.

Concept / Approach:
Bolts are normally made by hot or cold heading (upsetting) to form the head on a solid rod or wire, followed by thread rolling or cutting. Nuts are made by hot or cold forging with later tapping for the internal thread. Piercing is not the primary method because bolts and nuts are not hollow products; piercing is aimed at hollow products such as seamless tubes, rings, or hollow forgings.

Step-by-Step Solution:
Identify what hot piercing creates: a central cavity in a hot billet.Compare to bolt/nut geometry: bolts require solid shank; nuts require through-hole made by punching/drilling/tapping after forging, not by tube-making methods.Therefore, hot piercing is not extensively used for bolts and nuts.

Verification / Alternative check:
Process plans for fastener manufacture (automotive, construction) show heading and thread rolling lines rather than piercing mills; piercing is found in tube and pipe mills.

Why Other Options Are Wrong:
'Yes' misstates common industry practice; material-specific options are red herrings since the geometry, not alloy, dictates process choice.

Common Pitfalls:
Confusing nut hole punching with large-scale hot piercing for tubes; assuming any operation that makes a hole qualifies as hot piercing in the metallurgical sense.

Final Answer:
No