Product Specifications
| Model / Specification | M10–M105 |
| Material | Carbon Steel |
| Thread Size d |
M10 | M12 | M14 | M16 | M18 | M20 | M22 | M24 | M27 | M30 | M33 | M36 | M39 | ||
| P | Pitch | 1.5 | 1.75 | 2 | 2 | 2.5 | 2.5 | 2.5 | 3 | 3 | 3.5 | 3.5 | 3 | 3 | |
| e | Min. | 19.86 | 23.15 | 26.51 | 29.87 | 33.23 | 37.39 | 39.63 | 45.23 | 50.4 | 54.88 | 60.26 | 65.86 | 70.67 | |
| m | Type 1 | Max. | 8.4 | 10.8 | 12.8 | 14.8 | 15.8 | 18 | 19.4 | 21.5 | 23.8 | 25.6 | 28.7 | 31 | 33.4 |
| Min. | 8.04 | 10.37 | 12.1 | 14.1 | 15.1 | 17.9 | 18.1 | 20.2 | 22.5 | 24.3 | 27.4 | 29.4 | 31.8 | ||
| Type 2 | Max. | 10.3 | 12.3 | 14.3 | 16.4 | 18.4 | 20.4 | 22.4 | 24.4 | 27.4 | 30.4 | 33.5 | 36.5 | 39.5 | |
| Min. | 9.9 | 11.8 | 13.6 | 15.7 | 17.7 | 19.3 | 21.1 | 23.1 | 26.1 | 29.1 | 32.2 | 34.9 | 37.9 | ||
| s | Max. | 18 | 21 | 24 | 27 | 30 | 34 | 36 | 41 | 46 | 50 | 55 | 60 | 65 | |
| Min. | 17.73 | 20.67 | 23.67 | 26.67 | 29.67 | 33.38 | 35.38 | 40.38 | 45 | 49 | 53.8 | 58.8 | 63.1 | ||
| Weight/1000 pcs ≈ kg | Type 1 | 12 | 20 | 31 | 45 | 59 | 89 | 103 | 156 | 218 | 271 | 368 | 474 | 506 | |
| Type 2 | 15 | 23 | 35 | 50 | 69 | 101 | 119 | 177 | 251 | 322 | 429 | 558 | 598 | ||
| Thread Size d |
M42 | M45 | M48 | M52 | M56 | M64 | M70 | M76 | M82 | M90 | M100 | M105 | ||
| P | Pitch | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 | |
| e | Min. | 70.67 | 76.27 | 81.87 | 87.47 | 92.74 | 103.94 | 111.78 | 120.74 | 129.70 | 142.8 | 159.6 | 165.2 | |
| m | Type 1 | Max. | 34 | 36 | 38 | 42 | 45 | 51 | 56 | 61 | 66 | 72 | 80 | 84 |
| Min. | 32.4 | 34.4 | 36.4 | 40.4 | 43.4 | 49.1 | 54.1 | 59.1 | 64.1 | 70.1 | 78.1 | 82.1 | ||
| Type 2 | Max. | 42.5 | 45.5 | 48.5 | 52.5 | 56.5 | 64.5 | 70.5 | 76.5 | 82.5 | 90.5 | 100.5 | 105.5 | |
| Min. | 40.9 | 43.9 | 46.9 | 50.6 | 54.6 | 62.6 | 68.6 | 74.6 | 80.3 | 88.3 | 98.3 | 103.3 | ||
| s | Max. | 65 | 70 | 75 | 80 | 85 | 95 | 102 | 110 | 118 | 130 | 145 | 150 | |
| Min. | 63.1 | 68.1 | 73.1 | 78.1 | 82.8 | 92.8 | 99.8 | 107.8 | 115.8 | 127.5 | 142.5 | 147.5 | ||
| Weight/1000 pcs ≈ kg | Type 1 | 550 | 682 | 834 | 1014 | 1219 | 1678 | 2275 | 2599 | 3274 | 4279 | 6021 | 6598 | |
| Type 2 | 687 | 862 | 1064 | 1267 | 1530 | 2122 | 2844 | 3259 | 4093 | 5379 | 7526 | 8247 | ||
HEXAGON NUT FOR PETROCHEMICAL INDUSTRY — PRODUCT INTRODUCTION
The hexagon nut for petrochemical industry is a core fastener in flange connection assemblies for petrochemical plants. It is mainly manufactured according to standards such as SH/T 3404, HG/T 20634 (American system), and HG/T 20613 (European system), and must be paired with double-end studs of the same standard for use in critical connection points such as pipe flanges, valves, pressure vessels, heat exchangers, and towers. These nuts are classified by material characteristics into “special grade” (identified by material grade, such as 30CrMoA, 35CrMoA) and “commercial grade” (identified by performance grade, such as Grade 8, Grade 10, A2-50, etc.). Through strict control of material, heat treatment, and hardness, they ensure connection sealing integrity and structural integrity under harsh operating conditions such as high temperature, high pressure, hydrogen service, corrosion, and low temperature.
I. PRODUCT FEATURES
STRICT MATCHING OF MATERIAL AND PERFORMANCE TO OPERATING CONDITIONS: Classified according to temperature, pressure, and media corrosivity. Special grade nuts use Cr-Mo alloy steel or austenitic stainless steel, quenched and tempered, combining excellent high-temperature strength, resistance to relaxation, and low-temperature toughness.
HARDNESS GRADIENT DESIGN: Nut material is typically one grade lower or slightly lower in hardness than the matching stud (e.g., stud 35CrMoA paired with nut 30CrMoA), forming a hardness gradient to prevent thread galling under high temperature and pressure, facilitating disassembly and maintenance.
STANDARDIZED DIMENSIONS AND TYPES: Strictly follows standards for Type I (thin) and Type II (thick) hexagon nut dimensions. Type II nuts have higher load-bearing capacity and are mostly used in more severe operating conditions, ensuring bearing area and preloading force transmission.
RELIABLE QUALITY ASSURANCE: Requires batch-by-batch hardness inspection and proof load testing. Critical applications require high-temperature tensile testing, low-temperature impact testing, and spectrographic analysis to ensure no material mix-up and stable performance.
II. PRODUCT ADVANTAGES
WIDE COVERAGE OF EXTREME OPERATING CONDITIONS: From -196°C low temperature to over 600°C high temperature, from atmospheric pressure to high-pressure hydrogenation, strong corrosion, and toxic media, there are matching nut grades available, achieving multi-scenario coverage with one set of standards.
STRONG ANTI-GALLING CAPABILITY: Through reasonable stud-nut material and hardness pairing, combined with molybdenum disulfide and other lubrication treatments, the risk of thread galling and seizing during disassembly after high-temperature service is significantly reduced, shortening maintenance cycles.
MATURE STANDARDS, GOOD INTERCHANGEABILITY AND COMPLIANCE: Fully aligned with petrochemical industry standards, comparable with the internationally mainstream ASTM A194 system, standardized procurement, highly recognized by owners and design institutes, easy to pass safety reviews.
HIGH SERVICE LIFE AND SEALING RELIABILITY: Through precise control of material tempering stability and relaxation resistance, bolt preloading force can be effectively maintained during long-term high-temperature operation, preventing flange leakage caused by preloading force decay.
III. SCOPE OF APPLICATION
REFINING AND CHEMICAL PLANTS: High-temperature, high-pressure hydrogen service flange connections in atmospheric and vacuum distillation, catalytic cracking, reforming, hydrocracking, ethylene cracking, and other units.
FERTILIZER AND COAL CHEMICAL PLANTS: Sealing connections for critical equipment such as ammonia synthesis towers, urea synthesis towers, and high-pressure scrubbers.
LONG-DISTANCE OIL AND GAS PIPELINES AND STORAGE/TRANSPORTATION: Pipe flanges, valve covers, station header connections, etc., subject to pressure fluctuations and ambient temperature changes.
POWER GENERATION AND BOILER SYSTEMS: Flange fastening for power plant boiler drums, superheater headers, and high-temperature steam piping.
DEEP COLD AND AIR SEPARATION UNITS: Low-temperature connection systems using austenitic stainless steel nuts for liquefied natural gas (LNG) storage tanks, air separation cold boxes, etc.
