Titanium Fasteners with Passivation Treatment \| Gr2/Gr5/Gr7, Pickling+Passivation, MoS₂/PTFE Anti-Gall, EN 10204 3.1, Baoji

Product Overview

Reviewed and maintained by the Engineering Team, Shaanxi Qianyi Tuoda Technology Co., Ltd.

Titanium Fasteners with Passivation Treatment | Pickling + Passivation + Anti-Gall Lube, ASTM F468, MTC 3.1

Meta Description: Titanium Fasteners with passivation treatment — pickling removes iron contamination, nitric-acid passivation stabilizes the self-healing TiO₂ film, MoS₂/PTFE dry film controls galling. Gr2/Gr5/Gr7 per ASTM F468/F467, 100% PMI, EN 10204 3.1.

First, What Passivation Does (and Does NOT Do) on Titanium

Titanium already forms a dense, self-healing TiO₂ film in air/oxygen — that is why it resists seawater and chlorides. Passivation is not "adding rust-proofing from zero" like on stainless. Its job on a titanium fastener is:

• Remove free iron / shop dirt / machining smear from the thread root
• Strip uneven heat-tint from cutting
• Stabilize and slightly thicken the native oxide film
• Restore uniform silver-grey surface for audit/cleanliness

Passivation alone does not stop thread galling. Galling is solved by clean threads + anti-seize (MoS₂/PTFE/dry film) + matched grade — stated upfront, not buried.

Process Route (what "passivated" actually means here)

1. Degrease / alkaline clean
2. Pickling (HF-HNO₃ controlled, or citric+nitric for precision parts) — remove scale, control etch depth ~0.05-0.1mm
3. Thorough rinse (neutral pH verify — residual F⁻ destroys the film)
4. Passivation: nitric-acid system (room temp to ~50°C, controlled time), no over-concentration
5. Ultrasonic rinse + DI-water final rinse (blind holes/threads critical)
6. Dry, no stacking before fully dry
7. Optional: MoS₂ / PTFE dry-film lube on thread (anti-gall, not part of passivation)
8. 100% PMI + GO/NO-GO gauge + ferroxyl iron-check on request

Surface Options We Offer

Grade-by-Grade Note

• Gr2 (R50400): passivation straightforward, marine/chemical default
• Gr5 (R56400): passivation OK; galling control = dry-film lube mandatory, not optional
• Gr7 (R52400): Pd verified by chemistry; passivation same logic, reducing-acid duty
• Gr12: hot-brine crevice economy route

QC Release for Passivated Fasteners

• Free-iron check (ferroxyl) on request — surface Fe≈0 acceptable
• Neutral rinse-water pH record (no fluoride residue)
• PMI/XRF grade verify (Gr2≠Gr5≠Gr7 by colour)
• Thread GO/NO-GO 100%
• EN 10204 3.1: chemistry + tensile from bar heat
• Surface finish Ra stated if polished
• Lube type recorded on pack (MoS₂/PTFE/none)

Anti-Galling — Shipped With the Pack

• Passivation = surface cleanliness; anti-seize = joint survival
• Clean threads + MoS₂/PTFE dry film; never assemble dry
• Matched nut grade (Gr5+Gr5, not Gr5+Gr2 at high preload)
• Torque from validated preload (Ti E≈110 GPa, half of steel) — not steel table
• Re-check torque 24h after PTFE lube
• Galvanic: PTFE sleeve / dielectric washer when joining CS/Al

RFQ Template (copy-paste)

Fastener: bolt / screw / stud / nut / kit ___
Grade: Gr2(R50400) / Gr5(R56400) / Gr7(R52400) / Gr12 ___
Size + thread: M___ / UNC-__ / UNF-__  (pitch/class ___)
Finish required:
  [ ] Pickled + nitric passivated (natural grey)
  [ ] Polished + passivated
  [ ] Anodize colour ___ (ID only)
  [ ] MoS2 dry film / PTFE dry film on thread
  [ ] None (as-machined)
Free-iron (ferroxyl) test: Y/N
Ra target (if polished): ___
Medium + temp (drives grade): ___
Qty: ___
Cert: 3.1 / 3.2 (TPI ___)
Incoterm: EXW Baoji / FOB Shanghai / DAP ___

FAQ — Passivated Titanium Fasteners

Q1: Do Titanium Fasteners even need passivation?
A: Native TiO₂ film already protects them. Passivation is for removing iron contamination, scale and heat-tint — required by many chemical/marine/pharma specs, not cosmetic only.

Q2: Will passivation stop galling?
A: No. Galling needs anti-seize (MoS₂/PTFE) + matched grade + clean threads. We ship both notes together.

Q3: Nitric acid concentration?
A: Controlled nitric system (typically dilute, room-temp to ~50°C); not over-concentrated, not HF-only. Parameters fixed per grade + thread tolerance.

Q4: Anodize = better corrosion?
A: Colour anodize is ID coding. Hard anodize/MAO adds wear resistance when project-specified; base corrosion comes from TiO₂ film + grade choice.

Q5: Residual acid risk in threads?
A: Neutral-rinse verification + ultrasonic clean for blind holes; pH-neutral sign-off before pack.

Q6: Medical implant passivation?
A: F136/implants use project-specific passivation (e.g. ASTM F86-type protocol) — named on PO, not default industrial passivation.

Q7: Gr5 passivated + dry lube?
A: Recommended for high-preload/chassis/aerospace-adjacent — dry film is the real anti-gall step.

Q8: 3.2 possible?
A: TPI at PO stage; cannot be back-built from 3.1.

Q9: HF / dry chlorine / fuming nitric?
A: Titanium excluded — red line, no passivation workaround.

Q10: HS code?
A: 8108.90.00 WCO base; destination sub-heading via broker.

Request a Quote

Email: sales@[yourdomain].com

Send grade + size + finish (pickled/passivated/lube) + medium + qty. Reply in 24h: route, EXW/FOB price, cert scope, dispatch window.

About: Baoji Titanium Valley passivated fastener line — Gr2/R50400, Gr5/R56400, Gr7/R52400. Pickling removes iron, nitric passivation stabilizes the TiO₂ film, dry-film lube controls galling. ASTM F468/F467 finished route, 100% PMI + GO/NO-GO gauged, EN 10204 3.1. We do not sell "passivation = no galling" myth; pack states both. No dry assembly, no fluoride residue, no cert downgrade. Lot confirmed before PI; tag = MTC = heat.