ASTM A194 Stainless Heavy Hex Nuts
| Standard | ASTM A194 Grade 8 / ASME B18.2.2 · 8M |
|---|---|
| Material | SS316 |
| Strength Grade | 8 / 8M |
| Size Range | M12-M64 |
| Surface Treatment | Passivated |
01
Product Description
Product Description & Key Specifications
ASTM A194 Grade 8 / 8M stainless heavy hex nuts are pressure bolting nuts used with stainless ASTM A193 stud bolts in corrosive flange, valve, offshore, marine and renewable energy assemblies. This range is supplied in SS316 with ASME B18.2.2 dimensional reference and passivated surface condition.
Grade 8 and Grade 8M stainless nuts are not general-purpose DIN hex nuts. They are selected for stainless pressure bolting where nut grade, thread fit, heavy hex geometry, material traceability, passivation and certificate requirements must match the stud bolt specification. Grade 8M is commonly associated with molybdenum-bearing stainless service such as B8M stud bolting.
Common RFQs include M16, M20, M24, M30, M36, M42, M48 and M64 stainless heavy hex nuts for flange packages, offshore equipment, pumps, valves and marine renewable structures. Confirm the matching stud grade, thread series, operating temperature, corrosion environment and certificate level before ordering.
| Product type | ASTM A194 stainless heavy hex nuts for pressure bolting |
|---|---|
| Standards | ASTM A194 Grade 8 / Grade 8M / ASME B18.2.2 |
| Material | SS316 stainless steel |
| Strength grade | Grade 8 / 8M |
| Size range | M12-M64 |
| Common models | M16, M20, M24, M30, M36, M42, M48, M56, M64 |
| Thread type | Metric or project thread by matching stud bolt requirement |
| Surface finish | Passivated stainless surface |
| Matched hardware | ASTM A193 B8 / B8M stainless stud bolts and stainless washers where specified |
| Documentation | MTC, CoC, heat traceability, dimensional report and passivation report on request |
Dimensions & SpecificationsASME B18.2.2 Heavy Hex Nuts
Technical Drawing
Dimensional Table
| Parameter | 1 | 1/4 | 1/2 | 1-1/8 | 1-1/4 | 1-3/8 | 1-1/2 | 1-5/8 | 1-3/4 | 1-7/8 | 2 | 2-1/4 | 2-1/2 | 2-3/4 | 3 | 3/8 | 3/4 | 3-1/4 | 3-1/2 | 3-3/4 | 4 | 5/16 | 5/8 | 7/16 | 7/8 | 9/16 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| P | 8|12|20 | 20|28|32 | 13|20|28 | 7|12|18 | 7|12|18 | 6|12|18 | 6|12|18 | 6|12|18 | 5|8|12 | 6 | 4.5 | 4.5 | 4 | 4 | 4 | 16|24|32 | 10|16|20 | 4 | 4 | 4 | 4 | 18|24|32 | 11|18|24 | 14|20|28 | 9|14|20 | 12|18|24 |
| s/min | 1.575 | 0.448 | 0.85 | 1.756 | 1.938 | 2.119 | 2.3 | 2.481 | 2.662 | 2.844 | 3.025 | 3.388 | 3.75 | 4.112 | 4.475 | 0.669 | 1.212 | 4.838 | 5.2 | 5.562 | 5.925 | 0.546 | 1.031 | 0.728 | 1.394 | 0.909 |
| s/max | 1.625 | 0.5 | 0.875 | 1.812 | 2 | 2.188 | 2.375 | 2.562 | 2.75 | 2.938 | 3.125 | 3.5 | 3.875 | 4.25 | 4.625 | 0.688 | 1.25 | 5 | 5.375 | 5.75 | 6.125 | 0.562 | 1.062 | 0.75 | 1.438 | 0.938 |
| e/min | 1.796 | 0.556 | 0.969 | 2.002 | 2.209 | 2.416 | 2.622 | 2.828 | 3.035 | 3.242 | 3.449 | 3.862 | 4.275 | 4.688 | 5.102 | 0.763 | 1.382 | 5.515 | 5.928 | 6.341 | 6.755 | 0.622 | 1.175 | 0.83 | 1.589 | 1.037 |
| e/max | 1.876 | 0.577 | 1.01 | 2.093 | 2.309 | 2.526 | 2.742 | 2.959 | 3.175 | 3.392 | 3.608 | 4.041 | 4.474 | 4.907 | 5.34 | 0.794 | 1.443 | 5.774 | 6.207 | 6.64 | 7.073 | 0.65 | 1.227 | 0.866 | 1.66 | 1.083 |
| k/min | 0.956 | 0.218 | 0.464 | 1.079 | 1.187 | 1.31 | 1.433 | 1.556 | 1.679 | 1.802 | 1.925 | 2.155 | 2.401 | 2.647 | 2.893 | 0.341 | 0.71 | 3.124 | 3.37 | 3.616 | 3.862 | 0.28 | 0.587 | 0.403 | 0.833 | 0.526 |
| k/max | 1.012 | 0.25 | 0.504 | 1.138 | 1.251 | 1.378 | 1.505 | 1.632 | 1.759 | 1.886 | 2.013 | 2.251 | 2.505 | 2.759 | 3.013 | 0.377 | 0.758 | 3.252 | 3.506 | 3.76 | 4.014 | 0.314 | 0.631 | 0.441 | 0.885 | 0.568 |
02
Selection
Selection Advantages by Application
Stainless Flange Bolting
A194 Grade 8 / 8M nuts are used with stainless stud bolts in flange packages, valves, pumps and process equipment where corrosion resistance and pressure bolting traceability are required.
Oil and gas fastenersOffshore and Marine Renewable Equipment
SS316 8M heavy hex nuts support offshore auxiliaries, marine renewable structures and salt-spray exposed equipment when stainless stud bolting is specified.
Renewable energy fastenersPower and Utility Piping Systems
Passivated stainless heavy hex nuts can be used in corrosion-resistant piping, heat exchanger and utility equipment assemblies when compatible stainless studs are selected.
Power generation fasteners03
Assembly
Recommended Matching Products
04
Manufacturing
Manufacturing & Quality Control
Manufacturing CapabilityQuality Control
Hot forging or machining of SS316 heavy hex nut blanksSS316 material and heat number verification
Tapping to ASTM / ASME or project thread requirementThread gauge, across-flat, height and dimensional inspection
Passivation after machining or formingSurface cleanliness and passivation report support when specified
Nut supply alone or kitted with stainless stud boltsGrade marking, lot traceability and package label checks
Export packaging for flange and pressure bolting packagesMTC, CoC and inspection reports prepared on request
05
FAQ
Common Questions Before RFQ
What are ASTM A194 Grade 8 / 8M nuts used for?
They are stainless heavy hex nuts used for pressure bolting, commonly with ASTM A193 stainless stud bolts in corrosive flange, valve and equipment assemblies.
What is the difference between Grade 8 and 8M?
Grade 8 and 8M are stainless A194 nut grades. Grade 8M is commonly specified with molybdenum-bearing stainless bolting such as B8M service; follow the project specification.
Are these nuts passivated?
Yes. Passivated finish is available to improve stainless surface condition after forming, machining and tapping.
Can matching stainless studs be supplied?
Yes. Stainless heavy hex nuts can be supplied with compatible ASTM A193 B8 / B8M stud bolts when the stud grade and size schedule are confirmed.
What certificate documents are available?
MTC, CoC, heat traceability, dimensional reports and passivation reports can be supplied according to RFQ requirements.
Need ASTM A194 stainless heavy hex nuts?
Send grade, size, thread, matching stud grade, finish, quantity and certificate requirements. We can quote SS316 Grade 8 / 8M heavy hex nuts for stainless flange and offshore bolting packages.
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