National Standard Expansion Bolts | GB/T 22795 | Steel Sleeve Anchors for Concrete & Masonry | Metric & Inch
Product Title
National Standard Expansion Bolts | GB/T 22795 | Steel Sleeve Anchors for Concrete & Masonry | Metric & Inch
Product Summary
Longze High-Strength Full Thread Studs are high-performance fastening solutions engineered for high-pressure valves, flanges, and heavy structural steel connections. Manufactured in Yongnian,
China, our studs are precision-rolled and heat-treated to withstand extreme mechanical stress and thermal expansion.
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✔ Industry Standards: Fully compliant with ASTM A193 (B7, B8, B16) and DIN 975/976 (Class 8.8, 10.9, 12.9).
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✔ Precision Threading: Continuous full-thread design ensures maximum load distribution and easy adjustment.
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✔ Material Integrity: 100% heat-number traceability for critical safety applications.
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Standards: ASTM A193/A193M, DIN 975, DIN 976, ASME B18.31.2.
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Diameter Range: M6 to M100 | 1/4" to 4".
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Material Grade: B7, B7M, B16 (Carbon Steel) | B8, B8M (Stainless Steel) | Class 8.8, 10.9, 12.9.
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Surface Finish: Black Oxide, Xylan/PTFE, Zinc Plated, Hot Dip Galvanized.
Mechanical Properties & Tensile Strength
- Matching the material grade to the specific pressure and temperature requirements.
Grade / Property Class Tensile Strength Yield Strength Hardness Range Temp. Range (°C) ASTM A193 B7 125 ksi 105 ksi 26 to 35 HRC -29°C to 427°C ASTM A193 B16 125 ksi 105 ksi 26 to 35 HRC -29°C to 593°C Class 10.9 (DIN) 1040 MPa 940 MPa 32 to 39 HRC Structural Steel SS304 (B8 Class 2) 115 ksi 95 ksi 24 to 35 HRC Cryogenic Service
Full Thread Stud Dimensions & Pitch Reference
- Precise diameter and pitch configurations for both Metric and Unified Inch threads.
Thread Size Pitch (Metric) TPI (UNC/UNF) Root Diameter Match Nut Grade M16 (5/8") 2.0 mm 11 TPI 13.5 mm ASTM A194 2H M20 (3/4") 2.5 mm 10 TPI 16.9 mm ASTM A194 2H M24 (1") 3.0 mm 8 TPI 20.3 mm ASTM A194 2H M30 (1-1/8") 3.5 mm 7 TPI 25.7 mm ASTM A194 2H
Coating Selection & Corrosion Resistance
- Protecting your studs from flash rust and chemical corrosion in the field.
Surface Treatment Coating Thickness Salt Spray Test Best Applications Black Oxide (Oiled) N/A 24 to 48 Hours Oil & Gas (Indoor) Xylan / PTFE / Teflon 20 to 35 μm 1000+ Hours Offshore / Subsea Zinc Plated 5 to 12 μm 72 to 144 Hours General Construction Hot Dip Galvanized ≥ 55 μm 500 to 1000 Hours Outdoor Structural
Avoid Pitfalls:
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End-Face Identification: We prevent material mix-ups by stamping every stud with its specific grade (e.g., "B7") and manufacturer's mark on the end face.
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Hydrogen Embrittlement Prevention: For high-strength B7 and 10.9 studs, we implement a strict 400°F (204°C) baking process after plating to ensure zero brittle failure.
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Thread Engagement Quality: We use high-precision rolling dies to ensure no "burrs" or "flat spots" on the threads, even at lengths from 1 meter to 6 meters.
Perfect Fit Assembly:
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Flange Alignment: Our precision-cut studs provide balanced clamping force for ANSI and DIN flanges, ensuring leak-free performance.
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Complete Hardware Sets: Available with ASTM A194 2H Heavy Hex Nuts и F436 Hardened Washers for a "one-stop" assembly solution.
Quality Control & Logistics:
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ISO 9001 Certified: 5-step QC including ultrasonic flaw detection for heavy diameters (M42 to M100) and 100% thread gauge verification.
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Sea-Worthy Packaging: Studs are bundled with heavy-duty steel strapping and protected by moisture-proof oil-paper, shipped in reinforced wooden crates.
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Q: Can you provide studs in custom lengths for bridge projects? A: Yes, we can cut and chamfer studs to any length from 100mm to 6000mm with precision thread protection.
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Q: Do you provide MTC (Mill Test Certificates)? A: Yes, all ASTM A193 B7/B8 orders include a full MTC covering chemical heat analysis and mechanical testing.
- Email:eric@lzfastener.com What'sApp:+86 15350500528 WeChat:+86 18830006928 or 15350500528
- Planning a heavy-duty steel structure? Don't risk your project on low-grade fasteners. Send your requirements → Get an expert bolt recommendation + quote within 12 hours.
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