Our ASTM A193 B7M double-ended studs are manufactured from Cr-Mo alloy steel and heat treated to meet the stringent requirements of NACE MR0175 / MR0103 for sour (H₂S) service. Each stud is paired with an A194 grade 2HM heavy hex nut, engineered specifically for sulfide stress corrosion cracking (SSC) resistance in acidic environments.

This combination is the standard specification for bolting in oil and gas refineries, chemical processing plants, and high-temperature pressure vessel applications where standard B7 / 2H fasteners are not permitted due to hardness limits.

Standard: ASTM A193/A193M, ASTM A194/A194M, ASME B18.2.2

Material: A193 Gr. B7M (stud) + A194 Gr. 2HM (nut)

Type: Double-ended stud, fully threaded stud, heavy hex nut

Thread: UNC, 8UN, Grade 2A (stud) / 2B (nut)

Size Range: Imperial 1/4" – 4" | Metric M6 – M100

Temperature Range: -29°C to 538°C (-20°F to 1000°F)

SSC Resistance: Yes - compliant with NACE MR0175 / MR0103

C: 0.38–0.48 | Mn: 0.75–1.00 | P: ≤0.035 | S: ≤0.040

Si: 0.15–0.35 | Cr: 0.80–1.15 | Mo: 0.15–0.25

C: ≥0.15 | Mn: ≤1.00 | P: ≤0.04 | S: ≤0.05 | Si: ≤0.40

B7M Stud:

Min Tensile Strength: 100 KSI (689 MPa)

Min Yield Strength: 80 KSI (551 MPa)

Elongation: ≥18%

Hardness: HB 197–235 (max 235)

Heat Treatment: Quenched & tempered

2HM Nut:

Proof Load: 150 KSI (1034 MPa)

Hardness: HB 159–237

Heat Treatment: Quenched & tempered

The B7M grade is a low-hardness variant of B7, designed specifically for environments where sulfide stress cracking (SSC) is a risk:

Each order includes material traceability certified to ASTM specifications. We provide mill test reports (MTRs) with chemical composition, mechanical properties, and heat treatment records. Our facility is equipped with Brinell hardness testers, tensile testing machines, and impact testers for in-house quality verification.

Request a quote or ask a technical question about ASTM A193 B7M studs with A194 2HM nuts. We ship worldwide with full material traceability.