14 · Stainless · cold-welding risk on print
Stainless galling / cold-welding prevention on RFQ drawings
On stone cladding brackets, stainless structural splices, and heavy stainless plate joints, same-family stainless threads can gall (cold-weld) under dry install, high speed, or mismatched nut/bolt pairs. This desk locks what the controlling revision must name — mating pair, dry vs paste, install speed / torque notes — before any unit price is useful. Dashitou does not publish anti-seize brand charts or site torque tables here.
Define · what this RFQ is for
Use this desk when overseas buyers quote Dashitou stone · structural · heavy fasteners in A2 / A4 (or 304-/316-family) stainless and the print must address galling / cold-welding risk at install — especially stainless-on-stainless threads, long engagement, or dry assembly. You own joint design and engineer sign-off; we confirm which prevention notes appear on the revision, diameter × length, grade lock, and qty band against that revision.
Pair with A2 vs A4 coastal cladding (G10) when atmosphere drives grade, torque vs preload vs proof load (G13) when clamp figures sit beside paste notes, thread engagement vs grip (G11) when stack-up lengthens engagement, structural bolt class & coating (G8) when finish sits with the pair, nylon-insert vs prevailing-torque lock nut when lock-nut style changes stainless-on-stainless risk, 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 anti-seize brands, μ tables, or “never gall” guarantees on this public page.
Field desk · 01–06
-
Mating pair (bolt × nut / tap) Name stainless-on-stainless vs dissimilar nut/tap. Same-family threads raise galling risk under dry install. “Stainless hardware” without naming the pair invites dual quotes.
- Email example: A4 bolt × A4 nut (same family) · galling note required (Rev C)
- If missing: Open — do not assume a dissimilar nut from a catalog
-
Dry vs paste / anti-seize Dry stainless-on-stainless often needs an explicit paste rule or a written “dry allowed” exception. Name paste family or buyer-brand when the revision owns it; otherwise mark Open with a preference.
- Email example: Anti-seize paste required on threads · brand Open / buyer to name
- If Open: mark preference on the print or RFQ notes — see also G13 dry/lubed
-
Install speed / tool note High-RPM impact on stainless threads raises cold-weld risk. If the site rule limits speed or forbids impact, write it beside the galling note. Do not invent site RPM charts on this desk.
- Email example: Hand / low-speed only; impact forbidden on A4 pair (Rev C)
-
Grade lock & atmosphere Galling prevention does not replace A2 vs A4. Lock grade for corrosion / coastal exposure on the same revision — see G10. Finish / passivation remain separate lines.
- Email example: A4 coastal brackets · paste on threads · passivation Open
-
Diameter × length & engagement Long engagement and fine pitch can raise galling risk. Lock diameter × length with grip/engagement — see G11. Clamp figures stay on G13 when torque/preload is named.
- Email example: M12 × 60 A4; full nut height + 2P; paste required
-
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
- Mating pair named (stainless-on-stainless vs dissimilar nut/tap)
- Dry vs paste / anti-seize rule (or Open with preference)
- Install speed / impact note when site rules own it
- Grade lock (A2/A4) when atmosphere drives it — see A2 vs A4 coastal
- Controlling revision — see drawing handoff
Agree · before we number
Until the following are aligned, treat any figure as discussion only:
- Controlling revision locks mating pair + dry/paste rule (or marks Open with a preference)
- No invented anti-seize brand charts, “never gall” claims, or site RPM tables posted as policy here
- Grade (G10), engagement (G11), and torque/preload (G13) notes settled or linked in the same thread when those desks apply
- Samples and private-label marking only after pair, paste rule, 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 · stainless galling / cold-welding prevention
Is “use stainless hardware” enough to quote a galling-safe pair?
Usually no. Same-family stainless-on-stainless threads behave differently from a stainless bolt into a dissimilar nut or tap. Name the mating pair on the controlling revision, or mark Open with a preference rule. Vague “stainless OK” language often forces a resubmit.
When should an RFQ lock paste / anti-seize instead of dry install?
When the engineer or site rule expects stainless-on-stainless threads and forbids dry assembly, or when prior jobs showed galling. Do not invent a paste brand on this public desk without the print. Write dry vs paste beside any torque callout — see the torque vs preload desk.
Does choosing A4 instead of A2 prevent galling?
No. A2/A4 is a corrosion / atmosphere grade family callout. Galling is a friction / cold-weld risk at install. Treat grade lock and galling notes as separate lines on the RFQ and the print.
Can one RFQ mix dry zones and paste-required zones?
Yes, when zones are explicit on the BOM (for example paste on A4 cladding brackets, dry allowed on coated structural elsewhere). Ambiguous “paste optional” without zone ownership often splits the quote. Lock zones or mark Open with a preference rule.
What should I send so Dashitou can review galling notes cleanly?
Open Enquire / RFQ, then email the PDF/STEP or marked sketch to shizhanhao6@gmail.com in one thread. Include mating pair, dry/paste rule, install speed note if relevant, A2/A4 lock if relevant, diameter × length, qty band, and destination. Skim G10, G11, and G13 when those desks apply. No cart; no list prices on this site.
Next step
Skim A2 vs A4 coastal RFQ · torque / preload RFQ · engagement vs grip RFQ · nylon vs prevailing-torque RFQ · RFQ checklist, then open Enquire / RFQ. Direct email: shizhanhao6@gmail.com.