12 · Structural · head style on print
Flange bolts vs hex head on RFQ drawings
On stone cladding brackets, structural splices, and heavy baseplates, “hex bolt” on a BOM often hides a second choice: plain hex head (washer often required) versus flange / serrated flange head (integral washer face under the head). Lock the head style against the controlling revision before any unit price is useful — not a catalog head-swap.
Define · what this RFQ is for
Use this desk when overseas buyers quote Dashitou stone · structural · heavy fasteners and the print must separate hex head + washer pack from flange-head (including serrated flange when the revision names it). You own joint design and engineer sign-off; we confirm head style language, under-head bearing, diameter × length, and qty band against the controlling revision.
Pair with structural bolt class & coating (G8) when property class/finish matter, thread engagement vs grip (G11) when stack-up drives length, torque vs preload vs proof load when clamp language sits beside head style, A2 vs A4 coastal cladding when atmosphere drives stainless grade on flange nodes, cladding bracket slot vs hole (G5) when the hole type changes bearing, and drawing handoff for revision lock. Then open Enquire / RFQ.
Discuss · fields that change the quote
Each row below is a desk check. Missing rows stay Open — we do not invent flange OD charts, serration patterns, or torque tables on this public page.
Field desk · 01–06
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Head style on the controlling revision Name plain hex, flange (integral washer face), or serrated flange explicitly. “Hex bolt OK” without head style invites dual quotes.
- Email example: Head: DIN-style hex flange (non-serrated) per Rev D — not plain hex
- If missing: Open — do not swap flange for hex from a shelf photo
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Under-head bearing & washer rule Plain hex usually needs a named washer (or pad) under the head. Flange heads carry their own bearing face — still confirm if a separate washer is forbidden or required on soft cladding brackets.
- Email example: Plain hex + flat washer under head; flange SKU = no extra washer (Rev D)
- If Open: mark preference on the print or RFQ notes
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Slot / hole / clearance Flange OD vs washer OD can change cover over a slot. Cladding brackets with long slots often need the washer rule written beside the head style — see G5.
- Email example: M12 flange head over 14×28 slot; flange must cover slot short axis
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Diameter × length & grip Head style does not replace grip/engagement notes. Lock diameter × length with the stack — see G11.
- Email example: M16 × 70 flange head; grip 24 mm per Rev D
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Class / finish / nut set Property class and coating still matter — see G8. Nut / washer set must match the head-style rule on the same revision (do not mix serrated flange + captive lock washer unless the print says so).
- Email example: Class 8.8 zinc flake + matching nut; head = hex flange non-serrated
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Qty band & destination Mock-up joint set vs project lot; destination for packing notes. Discussion band is enough for the first reply.
- Email example: Qty band: mock-up 120 pcs → project lot TBD · dest AU
What must appear on the print
- Head style: plain hex vs flange vs serrated flange (or buyer standard callout)
- Washer / under-head rule when plain hex, or “no separate washer” when flange owns bearing
- Diameter × length and slot/hole note when flange OD matters
- Controlling revision — see drawing handoff
Agree · before we number
Until the following are aligned, treat any figure as discussion only:
- Controlling revision locks head style (or marks Open with a preference rule)
- No invented flange-OD, serration, or torque tables posted as site policy here
- Washer/isolation and class/finish settled or linked (G5 / G8 / G9 / G11) in the same thread
- Samples and private-label marking only after head style and diameter × length are clear
We do not invent certificates, plant area, or ranking badges here. Project documents that matter to the RFQ are shared privately when relevant.
FAQ · flange bolts vs hex head
Is “hex bolt” on the BOM enough to quote flange or plain hex?
Usually no. Plain hex and flange heads are different under-head bearing conditions. Name the head style on the controlling revision, or mark Open with a preference rule. Vague “hex bolt” language often forces a resubmit.
When should an RFQ lock flange head instead of plain hex + washer?
When the print or engineer rule wants an integral bearing face (or serrated flange for a named anti-rotation intent) and forbids a separate washer under the head. Do not upgrade plain hex to flange on this public desk without the print. Soft cladding brackets may still need a washer rule even with flange — write it.
Does choosing a flange head replace naming washers or isolation?
No. Flange replaces the under-head washer only when the revision says so. Isolation pads, flat washers on the nut side, and stone-on-steel stacks are separate lines — see the stone-on-steel RFQ desk when dissimilar metal applies.
Can one RFQ mix flange-head and plain-hex zones?
Yes, when zones are explicit on the BOM (for example flange on cladding brackets, plain hex + washer on heavy baseplates). Ambiguous “hex/flange OK” without zone ownership often splits the quote. Lock zones or mark Open with a preference rule.
What should I send so Dashitou can review head style cleanly?
Open Enquire / RFQ, then email the PDF/STEP or marked sketch to shizhanhao6@gmail.com in one thread. Include head style lock, washer/under-head rule, diameter × length, slot/hole if relevant, class/finish if relevant, qty band, and destination. Skim G5, G8, and G11 when those desks apply. No cart; no list prices on this site.
Next step
Skim structural bolt RFQ · cladding bracket RFQ · engagement vs grip RFQ · torque / preload RFQ · A2 vs A4 coastal RFQ · RFQ checklist, then open Enquire / RFQ. Direct email: shizhanhao6@gmail.com.