Base hot-rolled coil has gone flat at $1,180 a short ton. Plenty of buyers will read that as the top of the run. It isn’t, if what you actually buy is coated.
Nucor emailed customers on August 10 with revised galvanized and galvannealed coating extras, effective with orders confirmed for the week ending October 10, 2026. Steel Market Update, which maintains the mill price books, compared the old and new schedules and found increases of 7% to 20% across all thicknesses, averaging 11%.
Why this doesn’t show up in the number everyone watches
Galvanized and galvannealed don’t price off base hot-rolled alone. They price off base plus the coating extra, which is a separate published schedule. Watch only the HRC index and you’ll miss an 11% move on the product you’re buying.
The same day, Nucor set its hot-rolled consumer spot price at $1,160 per short ton for the week of August 10, up $5. That was the smallest of three consecutive weekly increases; the prior week rose $10. California Steel Industries, Nucor’s West Coast joint venture, went to $1,220, also up $5. Lead times held at three to five weeks. SMU’s assessed average domestic HR price was $1,180 on August 4 and unchanged at $1,180 on August 12.
Zinc is its own driver
Nucor told customers the increase was “consistent with our practice of monitoring the cost of zinc.” That’s a specific attribution and it matters. This isn’t a steel-price move and it isn’t a tariff move. It’s an input-cost mechanism with a separate commodity behind it, which means it can move again on its own schedule regardless of what HRC does.
SMU reported on August 14 that the hot-rolled-to-galvanized spread has widened over the past month, and separately on August 13 that the HRC-to-busheling-scrap spread keeps widening, a trend now running about a year.
What to do before October 10
The extra bites on orders confirmed the week ending October 10. That’s a real, plannable window to place coated orders against the old schedule, and it’s the most actionable detail in the announcement.
Longer term, anyone escalating a 2027 guaranteed maximum price off a hot-rolled index is under-hedged. Metal deck, light-gauge framing, joists, roofing, ductwork, guardrail and fasteners all ride the coating extra. If your escalation clause names HRC and your exposure is galvanized, the basis risk just got quantified for you.
The 11% average and the 7% to 20% range are SMU’s own calculations comparing Nucor’s published schedules. Nucor’s own language is the zinc sentence and the October 10 date.