Related Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
ASME B18.31.1M Metric Clamping Full Body Type Studs Dimension Standard
Precision Metric Stud Fasteners for High-Integrity Bolted Flange and Pressure Vessel Assemblies in Global Projects.
ASME B18.31.1M Metric Clamping Full Body Type Studs are metric-series unheaded threaded fasteners with threads at both ends and a full-diameter unthreaded body shank, expressed in SI dimensional units and engineered to provide consistent, uniform clamping load distribution across bolted flange joints, pressure vessel cover connections, heat exchanger bundles, and critical structural assemblies in global metric-standard engineering projects. The ASME B18.31.1M standard defines metric dimensional requirements for body diameter, overall stud length, thread length at each end, thread pitch, and body diameter tolerances — ensuring precise dimensional compliance for full-body clamping studs procured from multiple global suppliers for large-scale international industrial projects. When manufactured to ASTM A1082, the specification for high-strength stainless steel bolting material, these metric full-body clamping studs provide exceptional corrosion resistance paired with the controlled clamping performance required for offshore oil and gas flanges, desalination plant pressure equipment, LNG terminal piping, and chemical process heat exchangers operating in aggressive saline and chemical service environments. The full-body design ensures that the elastic stretch of the stud under bolt load is distributed uniformly along the full shank length, providing predictable bolt preload behavior and improved fatigue resistance in gasketed joints subject to pressure cycling and thermal expansion loads. ASTM A1082 metric full-body clamping studs are available with EN 10204 Type 3.1 documentation for full material traceability.
ASME B18.31.1M Metric Clamping Full Body Type Studs Dimensions (mm)
| Nominal Size Diameter, D |
Thread Length, B | UMax. = 2P |
Nominal Length, L | Body Diameter, DS | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| LT ≤ 250 | 250 < LT ≤ 400 | LT > 400 | Max. | Min. (by Length) | ||||||||
| Min. | Max. | Min. | Max. | Min. | Max. | Range | Incr. | LT ≤ 150 | LT > 150 | |||
| M1.6 | 9.2 | 9.9 | - | - | - | - | 0.7 | 25-50 | 5 | 1.60 | 1.29 | 1.29 |
| M2 | 10 | 10.8 | - | - | - | - | 0.8 | 25-50 | 5 | 2.00 | 1.65 | 1.65 |
| M2.5 | 11 | 11.9 | - | - | - | - | 0.9 | 30-50 | 5 | 2.50 | 2.12 | 2.12 |
| M3 | 12 | 13 | - | - | - | - | 1 | 30-50 | 5 | 3.00 | 2.58 | 2.58 |
| M4 | 14 | 15.4 | - | - | - | - | 1.4 | 35-90 | 5 | 4.00 | 3.43 | 3.43 |
| M5 | 16 | 17.6 | - | - | - | - | 1.6 | 40-90 | 5 | 5.00 | 4.36 | 4.36 |
| M6 | 18 | 20 | 24 | 26 | - | - | 2 | 50-90 100-160 |
5 10 |
6.00 | 5.82 | 5.70 |
| M8 | 18 | 20.5 | 26.5 | 24 | - | - | 2.5 | 50-90 ≥ 100 |
5 10 |
8.00 | 7.78 | 7.64 |
| M10 | 26 | 29 | 32 | 35 | 45 | 48 | 3 | 60-160 ≥ 180 |
10 20 |
10.00 | 9.78 | 9.64 |
| M12 | 30 | 33.5 | 36 | 39.5 | 49 | 52.5 | 3.5 | 60-160 ≥ 180 |
10 20 |
12.00 | 11.73 | 11.57 |
| M14 | 34 | 38 | 40 | 44 | 53 | 57 | 4 | 80-160 ≥ 180 |
10 20 |
14.00 | 13.73 | 13.57 |
| M16 | 38 | 42 | 44 | 48 | 57 | 61 | 4 | 90-160 ≥ 180 |
10 20 |
16.00 | 15.73 | 15.57 |
| M20 | 46 | 51 | 52 | 57 | 65 | 70 | 5 | 100-160 > 180 |
10 20 |
20.00 | 19.67 | 19.48 |
| M24 | 54 | 60 | 60 | 66 | 73 | 79 | 6 | 130-160 ≥ 180 |
10 20 |
24.00 | 23.67 | 23.48 |
| M30 | 66 | 73 | 72 | 79 | 85 | 92 | 7 | 150-160 ≥ 180 |
10 20 |
30.00 | - | 29.48 |
| M36 | 78 | 86 | 84 | 92 | 97 | 105 | 8 | ≥ 200 | 20 | 36.00 | - | 35.38 |
| M42 | 90 | 99 | 96 | 105 | 109 | 118 | 9 | ≥ 240 | 20 | 42.00 | - | 41.38 |
| M48 | - | - | 108 | 118 | 121 | 131 | 10 | ≥ 280 | 20 | 48.00 | - | 47.38 |
| M56 | - | - | 124 | 135 | 137 | 148 | 11 | ≥ 300 | 20 | 56.00 | - | 55.26 |
| M64 | - | - | 140 | 152 | 153 | 165 | 12 | ≥ 340 | 20 | 64.00 | - | 63.26 |
| M72 | - | - | 156 | 168 | 169 | 181 | 12 | ≥ 380 | 20 | 72.00 | - | 71.26 |
| M80 | - | - | 172 | 184 | 185 | 197 | 12 | ≥ 400 | 20 | 80.00 | - | 79.26 |
| M90 | - | - | - | - | 205 | 217 | 12 | ≥ 440 | 20 | 90.00 | - | 89.13 |
| M100 | - | - | - | - | 225 | 237 | 12 | ≥ 480 | 20 | 100.00 | - | 99.13 |
ASME B18.31.1M Metric Full Body Clamping Type Studs Length Tolerances (mm)
| Nominal Length | Tolerance | |
|---|---|---|
| Over | Through | |
| 6 | 10 | ± 0.29 |
| 10 | 18 | ± 0.35 |
| 18 | 30 | ± 0.42 |
| 30 | 50 | ± 0.50 |
| 50 | 80 | ± 0.95 |
| 80 | 120 | ± 1.10 |
| 120 | 180 | ± 1.25 |
| 180 | 250 | ± 1.45 |
| 250 | 315 | ± 1.60 |
| 315 | 400 | ± 1.80 |
| 400 | 500 | ± 2.00 |
| >500 | ... | ± 5.00 |
Frequently Asked Questions
What stainless steel grades does ASTM A1082 cover for stud bolts?
ASTM A1082 covers duplex grades (S31803/2205, S32205/2205, S32750/2507, S32760/Zeron 100, S39277/AL-6XN) and precipitation-hardening grades (S17400/17-4 PH, S17700/17-7 PH, S15700/15-7 PH, S35500/AM-355) - all available for this product family at TorqBolt.
What is the standard dimensional reference for these stud bolts?
This product follows ASME B18.31 1M, the dimensional standard for stud bolts in stainless steel. Material chemistry, mechanical properties and heat treatment follow ASTM A1082/A1082M. TorqBolt supplies both inch-series and metric sizes per the applicable ASME or ISO drawing.
Are A1082 stud bolts suitable for sour service (NACE MR0175)?
Yes, with hardness control. NACE MR0175 / ISO 15156 permits duplex grades S31803, S32205, S32750, S32760 at 28 HRC max for sour service. 17-4 PH (S17400) at H1150 condition (28 HRC) is the most common PH grade qualified for sour service. TorqBolt provides NACE-MR0175 compliant heat-treat reports.
What is the typical strength of A1082 super-duplex 2507 (S32750) stud bolts?
Super-duplex 2507 (S32750) per A1082: tensile 116 ksi (800 MPa) min, yield 80 ksi (550 MPa) min, elongation 15% min, 32 HRC max. PREN ≈ 42 - suitable for seawater, brine and chloride-rich pressure-vessel service. Higher strength than austenitic A193 B8M while offering pitting resistance well above 304/316.
References & Standards
- ASTM A1082 / A1082M - Standard Specification for High-Strength Precipitation-Hardening and Duplex Stainless Steel Bolting for Special-Purpose Applications (current edition 2016, active)
- ASTM A962 / A962M - General Requirements for Special-Purpose Bolting Materials
- ASTM A370 - Mechanical Testing of Steel Products
- NACE MR0175 / ISO 15156 - Sour-service hardness limits for petroleum & natural gas industries
- ASME B18 series - Dimensional standards for bolts, screws, nuts, studs
- ISO 4032 / 4033 / 4035 - Metric hexagon nut dimensional standards
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