Direct Answer
A hold point is a mandatory inspection stop in the fabrication process — no work proceeds past that point until an inspector has reviewed and approved the previous work. Hold points are used for critical operations: pre-weld fit-up, post-weld visual inspection, bolt pretensioning verification, and surface prep before coating. They are required by the project specification or the shop's AISC certification requirements.
Full Explanation
A witness point is similar but optional — the inspector has the right to witness but work can proceed if they don't show. A hold point is absolute — work stops until release. Common hold points in structural steel fabrication: (1) Pre-weld inspection — fit-up, joint geometry, preheat. (2) Post-weld visual — before NDT or before surface prep. (3) UT inspection — for Demand Critical welds. (4) First article — first complete assembly inspected before running quantity. (5) Pre-blast inspection — before SSPC blasting, verify all welds and mechanical operations are complete.
What This Means for Your Shop
Build hold points into your production schedule as real time allocations, not zero-duration events. A hold point for UT inspection on 30 moment connection welds may require the UT contractor on site for a full day — plan for this in your schedule.
Common Mistakes
Treating hold points as paperwork events rather than actual production stops. A hold point that gets signed off without inspection is a QC failure — and if discovered later, creates more extensive rework and liability.
Recommended Process
List all hold points in your QC plan at project kickoff. Assign responsibility for scheduling the inspector at each hold point. Build 24–48 hours of advance notice into your inspection scheduling so the inspector can be on site when the hold point is reached.