ASTM A563 Structural Hex Nuts
| Standard | ASTM A563 / ASTM F3125 ref |
|---|---|
| Material | ASTM A563 Grade DH / 1045 / 35K |
| Strength Grade | Grade DH / Grade 10 equivalent |
| Size Range | M12-M64 / 1/2"-2" |
| Surface Treatment | Plain / HDG / Zinc Flake |
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Product Description
Product Description & Key Specifications
ASTM A563 structural hex nuts are specified for structural bolting assemblies used in steel frames, bridges, towers and infrastructure connections. Grade DH nuts are commonly paired with ASTM F3125 high-strength structural bolts such as A325 and A490 systems when the project requires compatible structural nut performance.
A563 nuts should be selected by structural bolting system rather than by size alone. The correct order should confirm nut grade, bolt grade, thread series, coating, lubrication, washer requirement and whether the project requires rotational capacity, proof load, hardness or lot traceability documentation.
Plain finish is used in controlled or specified steelwork, hot-dip galvanized nuts are common for outdoor bridges and structures, and zinc flake coating may be selected where controlled coating thickness and corrosion performance are required. Coated structural nuts must maintain thread fit with the selected bolt finish.
| Product type | ASTM A563 structural hex nuts / structural heavy hex nuts |
|---|---|
| Standards | ASTM A563 / ASTM F3125 reference |
| Material | ASTM A563 Grade DH / 1045 / 35K |
| Strength grade | Grade DH / Grade 10 equivalent |
| Size range | M12-M64 / 1/2 in-2 in |
| Common models | M16, M20, M22, M24, M30, 3/4 in, 7/8 in, 1 in, 1-1/4 in |
| Thread type | UNC or metric thread by structural bolt system |
| Surface finish | Plain / Hot-dip galvanized / Zinc flake |
| Matched hardware | ASTM F3125 A325 / A490 bolts and ASTM F436 hardened washers |
| Documentation | MTC, CoC, hardness, proof load and coating report on request |
Dimensions & SpecificationsASME B18.2.6 Heavy Hex Nuts
Technical Drawing
Dimensional Table
| Parameter | 1 | 1/2 | 1-1/8 | 1-1/4 | 1-3/8 | 1-1/2 | 3/4 | 5/8 | 7/8 |
|---|---|---|---|---|---|---|---|---|---|
| P | 8 | 13 | 7 | 7 | 6 | 6 | 10 | 11 | 9 |
| k/max | 1.012 | 0.504 | 1.139 | 1.215 | 1.378 | 1.505 | 0.758 | 0.631 | 0.885 |
| k/min | 0.956 | 0.464 | 1.079 | 1.187 | 1.31 | 1.433 | 0.71 | 0.587 | 0.833 |
| s/max | 1.625 | 0.875 | 1.812 | 2 | 2.188 | 2.375 | 1.25 | 1.062 | 1.438 |
| s/min | 1.575 | 0.85 | 1.756 | 1.938 | 2.119 | 2.3 | 1.212 | 1.031 | 1.394 |
| e/min | 1.796 | 0.969 | 2.002 | 2.209 | 2.416 | 2.622 | 1.382 | 1.175 | 1.589 |
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Selection
Selection Advantages by Application
Bridge and Steel Frame Bolting
A563 Grade DH nuts are used with high-strength structural bolts for bridge splice plates, steel frame joints and infrastructure connections. Common sizes include M20, M22, M24, 3/4 in and 7/8 in.
Construction fastenersASTM F3125 Bolt Assemblies
When the project specifies ASTM F3125 A325 or A490 bolt assemblies, A563 nut grade and F436 washer compatibility should be confirmed together instead of purchasing nuts as isolated hardware.
Structural bolt assembliesOutdoor Steel Structures
HDG or zinc flake A563 structural nuts support outdoor towers, platforms and exposed steelwork where corrosion protection, coating compatibility and lot traceability matter.
Power generation fasteners03
Assembly
Recommended Matching Products
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Manufacturing
Manufacturing & Quality Control
Manufacturing CapabilityQuality Control
Hot forging and heat treatment for Grade DH structural nutsMaterial grade and heat number verification before production
Tapping and chamfering to ASTM / project thread requirementThread gauge, proof load and hardness inspection by lot
Plain, HDG or zinc flake surface finishingCoating thickness, thread fit and visual inspection after finish
Structural bolt-nut-washer assembly supplyAssembly compatibility and rotational capacity support when specified
Project packaging by heat, lot, size and coatingMTC, CoC and coating documents matched to package labels
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FAQ
Common Questions Before RFQ
What are ASTM A563 Grade DH nuts used for?
They are used in high-strength structural bolting assemblies, commonly with ASTM F3125 A325 or A490 bolts and ASTM F436 hardened washers.
Can A563 nuts replace ASTM A194 nuts?
No. A563 is a structural nut standard, while A194 is a pressure bolting nut standard. Substitution should only be made if the project engineer approves it.
Which finish is best for outdoor structural bolting?
Hot-dip galvanized finish is common for outdoor structural steel, while zinc flake may be selected for controlled coating thickness and corrosion performance.
Do structural nuts require matching washers?
Many structural assemblies specify ASTM F436 hardened washers. The need for washers depends on the bolt system, connection design and installation method.
Can you supply structural bolt assemblies?
Yes. Structural nuts can be supplied with compatible bolts and hardened washers by standard, grade, size, coating and project lot requirements.
Need ASTM A563 structural nuts?
Send your bolt grade, nut grade, size, thread, coating, washer requirement and test documentation needs. We can quote A563 Grade DH nuts alone or as complete structural bolting assemblies.
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