Special Fasteners
Beyond Standard · Engineered for Extreme Conditions
Special materials, oversized dimensions, custom shapes, extreme corrosion resistance — when standard parts aren’t enough, Rongrun Fasteners delivers engineering-grade custom solutions, MOQ from 500 pcs, 14–28 day lead time.
6 Categories of Special Fasteners
Covering oil & gas, marine engineering, high temperature/pressure, corrosion resistance and other extreme conditions — one-stop custom service from material selection to surface treatment
Pipeline Flange Bolting Sets
Pipeline Flange Bolting Sets · ASME / ASTM
- Stud Bolts B7 / B8 / L7 M12–M100
- Heavy Hex Nuts A194 2H / 8M Matched Supply
- Temperature Range -196°C ~ +600°C
- Pressure Class ASME 150 ~ 2500#
- Surface Treatment Phosphating, Dacromet, Cadmium Plating
High Corrosion-Resistant Marine Fasteners
Marine Fasteners · 316L / Duplex / Inconel
- Stainless 316L Bolts & Nuts M6–M64
- Duplex Stainless 2205 / 2507 High-Strength Marine Grade
- Inconel 625 / 718 Ultra Corrosion-Resistant
- Titanium Grade 2 / Grade 5 Lightweight High-Strength
- Salt Spray Test ≥ 2000 hours
Heavy Anchor Bolts
Heavy Anchor Bolts · M80–M160 · Custom Length
- Size Range M80 ~ M160
- Length Custom, up to 12m
- Material 42CrMo / S355J2
- Surface Treatment Hot-Dip Galvanized 85–100μm
- Strength Grade 4.6 / 8.8 / 10.9
Power Transmission Tower Bolts
Tower Bolts · GB/T 3632 · 10.9S / 8.8S
- Torshear High-Strength Bolt M16–M30
- Large Hex High-Strength Bolt M12–M36
- Strength Grade 8.8S / 10.9S
- Standard GB/T 3632 / 1228
- Surface Zinc Plated / Hot-Dip Galvanized
High-Temperature Alloy Fasteners
High-Temp Fasteners · Alloy 600 / 800 / A286
- Alloy 600 / Inconel 600 Up to 1000°C
- A286 Stainless Alloy Steel Up to 700°C
- Alloy 800 / 825 Oxidation/Corrosion Resistant
- Size M6 ~ M64
- Available Thermal Analysis + Mechanical Test Report
Custom Non-Standard & OEM Parts
Custom Non-Standard · To Drawing · MOQ 500 pcs
- Cold-Formed Special Head Bolts To Drawing
- Special Threads (Trapezoidal/Buttress/Multi-Start) Custom
- OEM Private Label Packaging MOQ 500 pcs
- Dacromet / Geomet Coating Custom Corrosion Protection
- Third-Party Inspection SGS / BV / TÜV
Custom Order Process
From requirement to delivery, standard process takes 14–28 days
Submit Requirement
Send drawings, specs or samples, noting material, quantity and destination
Technical Review
Engineers confirm feasibility within 24 hours, with material and process recommendations
Quote Confirmation
Complete quote including production, testing, packaging and FOB/CIF freight
Sample Approval
Samples provided before mass production (can be sent to buyer or third-party inspector)
Production + Testing
Full quality tracking, with chemical composition, mechanical and dimensional reports
Shipping + Documents
Packing list, invoice, MTC, Certificate of Origin provided; SGS on-site inspection supported
Available Materials
Covering carbon steel, alloy steel, stainless steel, nickel alloys and titanium
Carbon Steel / Alloy Steel
Q235, 45#, 42CrMo, 40Cr
Grade 4.6–12.9
Stainless Steel
304 / 316 / 316L
321 / 410 / 2205 / 2507
Nickel-Based Alloys
Inconel 600 / 625 / 718
Alloy 800 / 825 / A286
Titanium
Grade 2 (Commercially Pure)
Grade 5 (Ti-6Al-4V)
Copper Alloy / Brass
C36000 Brass, C46400 Naval Brass
For low-spark explosion-proof applications
ASTM Series
A193 B7/B8, A307, A325
A490, A354 Gr.BC/BD
Have a Custom Requirement?
Send us your drawing or spec sheet — our engineers will provide a feasibility assessment and quote within 24 hours