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 in refinery and power plant environments.

• ✔ 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 during flange assembly.

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• ✔ Material Integrity: 100% heat-number traceability for critical safety applications.

• Standards: ASTM A193/A193M, DIN 975, DIN 976, ASME B18.31.2.

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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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• Diameter Range: M6 to M100 | 1/4" – 4".

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• Length: Custom cut-to-length up to 6 meters (12ft/20ft).

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Mechanical Properties & Tensile Strength

• Matching the material grade to the specific pressure and temperature requirements of your project.

• Grade / Property Class	Tensile Strength	Yield Strength	Hardness Range	Temp. Range (°C)
  ASTM A193 B7	125 ksi	105 ksi	26 – 35 HRC	-29°C to 427°C
  ASTM A193 B16	125 ksi	105 ksi	26 – 35 HRC	-29°C to 593°C
  Class 10.9 (DIN)	1040 MPa	940 MPa	32 – 39 HRC	Standard Structural
  SS304 (B8 Class 2)	115 ksi	95 ksi	24 – 35 HRC	Cryogenic to 800°C

 

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 - 48 Hours	Oil & Gas (Indoor)
  Xylan / PTFE / Teflon	20 – 35 μm	1000+ Hours	Offshore / Subsea
  Zinc Plated	5 – 12 μm	72 - 144 Hours	General Construction
  Hot Dip Galvanized	≥ 55 μm	500 - 1000 Hours	Outdoor Structural

Avoid Pitfalls:

• 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, ensuring 100% onsite compliance.

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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 eliminate internal stress and prevent sudden

• 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, allowing for smooth nut fitment even at lengths over 1 meter.

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Perfect Fit Assembly:

• Flange Alignment: Our precision-cut studs provide balanced clamping force for ANSI and DIN flanges, ensuring leak-free performance in pressure-sealed systems.

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• Complete Hardware Sets: Available with ASTM A194 2H Heavy Hex Nuts Und F436 Hardened Washers for a "one-stop" heavy-duty assembly solution.

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Quality Control & Logistics:

• ISO 9001 Certified: 5-step QC including ultrasonic flaw detection for heavy diameters (over 1-1/2") 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 from our Yongnian facility.

• Q: Can you provide studs in custom lengths for bridge projects? A: Yes, we can cut and chamfer studs to any length up to 6 meters (20 feet) with precision thread protection.

• Q: Do you provide MTC (Mill Test Certificates)? A: Yes, all ASTM A193 B7/B8 orders include a full MTC covering chemical heat analysis, tensile strength, yield strength, and hardness.

• Email:eric@lzfastener.com  What'sApp:+86 15350500528 WeChat:+86 18830006928 or 15350500528