Boulons & Goujons
Goujons filetés, boulons hex et écrous hex lourds en acier allié (A193 B7) et inoxydable (A193 B8M) — stockés en Tunisie pour les assemblages à brides.
Demander un devisFasteners for Flanged Joints and Pressure Equipment
Fasteners — stud bolts, hex bolts and nuts — are the critical load-bearing elements of every flanged connection. Correct bolt material, grade and torque are essential to achieving and maintaining an effective gasket seal.
Tecflow Energy stocks fully threaded stud bolts with two heavy hex nuts per ASME B16.5 flange bolt requirements, in carbon steel alloy (A193 B7/A194 2H) and stainless steel (A193 B8M/A194 8M) grades.
Types de Boulons & Goujons en stock
Stud Bolts — A193 B7 / A194 2H
The most common flange bolting material in oil & gas and petrochemical service. Chrome-molybdenum alloy steel, heat treated, with 2H heavy hex nuts.
- All sizes for ASME B16.5 #150–#2500 flange bolting
- Alloy steel: ASTM A193 Grade B7 / ASTM A194 Grade 2H
- Continuous thread (stud) or threaded both ends
- NACE MR0175 compliant grade B7M / 2HM available
Stainless Steel Stud Bolts — B8M / 8M
Austenitic stainless steel stud bolts for corrosive service, cryogenic applications and compatibility with stainless piping.
- A193 B8M (316SS) / A194 8M nuts
- Strain-hardened (Class 2) for higher strength
- For use in chemical, cryogenic and marine service
- Not suitable for H₂S service (NACE restriction)
Heavy Hex Nuts
Heavy hex nuts to ASME B18.2.2 supplied separately or as matched sets with stud bolts. Grades 2H, 2HM, 8M.
- Grade 2H: Standard alloy steel nut for B7 bolts
- Grade 2HM: NACE compliant with B7M studs
- Grade 8M: Stainless steel for B8M studs
- Full thread engagement and seat tightness verified
Special Fasteners
High-strength low alloy (HSLA) bolts for sour service, L7 low-temperature bolts, B6 (410SS) trim bolts and other grades to project specification.
- A193 L7 / A194 7 — Low temperature service (to −101°C)
- A193 B6 — 410SS for valve trim and small bore flanges
- A453 Gr.660 (Alloy 718) — Elevated temperature service
- Galvanised and PTFE/Xylan coated bolts available
Normes & Spécifications
Bolt Standards
- ASTM A193 — Alloy and SS bolt materials
- ASTM A194 — Nut materials
- ASTM A320 — Low temperature fasteners
- API 20E — Alloy and carbon steel bolting for API equipment
Dimensional Standards
- ASME B18.2.1 — Hex cap screws and bolts
- ASME B18.2.2 — Square and heavy hex nuts
- ASME B1.1 — Unified inch screw threads
- ASME B16.5 Appendix — Flange bolt dimensions
Testing
- EN 10204 3.1 material certificates
- Hardness testing (Brinell)
- Tensile and yield strength verification
- NACE compliant grades: hardness ≤22 HRC (B7M)
Marking
- Grade marking on bolt head / nut face
- Heat number traceability
- NACE grade markings as applicable
- Country of origin certification
Pourquoi acheter chez Tecflow ?
Standard B7/2H stud bolt sets stocked for common flange sizes and pressure classes.
B7M/2HM NACE sour service grade stud bolts stocked for H₂S environments.
EN 10204 3.1 material certificates and hardness reports available.
Pre-counted bolt sets per flange schedule for project supply — saves site time.
Questions fréquentes
What is the difference between A193 B7 and B7M?
Both are chromium-molybdenum alloy steel stud bolts. B7 is the standard grade with higher strength. B7M is the NACE MR0175 compliant grade — the same alloy but with a maximum hardness restriction of 22 HRC to prevent hydrogen embrittlement in sour (H₂S) service. B7M must be used with matching 2HM nuts in sour service applications.
How do I determine the correct bolt size for my flange?
Bolt sizes for ASME B16.5 flanges are standardized — the number of bolts, bolt diameter and stud length are defined for each flange size and pressure class. We can provide flange bolting tables for any size/class combination on request.
Need Bolting for Your Flange Schedule?
Send us your flange schedule and we'll calculate the bolt sets and confirm pricing within 24 hours.