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Weathering Steel Heavy Hex Nuts (ASTM A563 Grade C3 / DH3) - Grade C3 / Grade DH3 - Weathering Steel / ASTM A563 C3 / DH3 - hex body with internal thread

Weathering Steel Heavy Hex Nuts

StandardASTM A563 Grade C3 · DH3
MaterialWeathering Steel / ASTM A563 C3 / DH3
Strength GradeGrade C3 / Grade DH3
Size RangeM12-M36 / 1/2"-1-1/2"
Surface TreatmentWeathering / Unplated
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01

Product Description

Product Description & Key Specifications

Weathering steel heavy hex nuts are supplied for ASTM A325 Type 3 and weathering steel structural bolt assemblies used in bridges and exposed infrastructure. Common references include ASTM A563 Grade C3 and Grade DH3, with metric sizes M12-M36 and inch sizes from 1/2 in to 1-1/2 in.

These nuts are normally supplied unplated to maintain compatible corrosion behavior with weathering steel bolts and connected steel members. Nut chemistry, proof load grade, thread fit, washer pairing and lot traceability should match the structural bolting package required by the project.

Grade C3 is a weathering steel nut grade used for compatible atmospheric corrosion behavior, while DH3 provides higher-strength weathering heavy hex nut capability where specified. Final selection should follow the bolt grade, structural design and project standard.

Product typeWeathering steel heavy hex nuts
StandardsASTM A563 Grade C3 / DH3
MaterialWeathering Steel / ASTM A563 C3 / DH3
Strength gradeGrade C3 / Grade DH3
Size rangeM12-M36 / 1/2 in-1-1/2 in
Common modelsM16, M20, M22, M24, M30, 3/4 in, 7/8 in, 1 in
Thread typeMetric or UNC heavy hex nut thread by order
Surface finishWeathering / Unplated
DocumentationMTC, CoC, lot traceability and dimensional report on request
Dimensions & SpecificationsASME B18.2.6 Heavy Hex Nuts

Technical Drawing

ASME B18.2.6 technical drawing

Dimensional Table

Parameter11/21-1/81-1/41-3/81-1/23/45/87/8
P813776610119
k/max1.0120.5041.1391.2151.3781.5050.7580.6310.885
k/min0.9560.4641.0791.1871.311.4330.710.5870.833
s/max1.6250.8751.81222.1882.3751.251.0621.438
s/min1.5750.851.7561.9382.1192.31.2121.0311.394
e/min1.7960.9692.0022.2092.4162.6221.3821.1751.589
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Selection

Selection Advantages by Application

Weathering Steel Bridge Bolting

A563 C3 / DH3 heavy hex nuts are used with A325 Type 3 bolts in bridge girders, splice plates and exposed steel connections. Common RFQs include M20, M22, M24 and 7/8 in nuts.

Bridge fasteners

Exposed Infrastructure Assemblies

Unplated weathering heavy hex nuts support compatible patina behavior in pedestrian bridges, towers, railings and outdoor steelwork. Confirm washer and bolt chemistry compatibility.

Infrastructure fasteners

Transit / Railway Steel Structures

Weathering heavy hex nuts may be specified for exposed rail infrastructure connections where the structural bolt system requires weathering steel compatibility and lot traceability.

Railway fasteners
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Assembly

Recommended Matching Products

Weathering Steel Structural Bolts (ASTM A588 / ASTM A325 Type 3) - A325 Type 3 / 10.9 - Weathering Steel - head, shank and thread geometry
Weathering Steel Structural BoltsCompatible A325 Type 3 / weathering bolt pairing.
ASTM F436 Hardened Washers (ASTM F3125 ref) - Hardened - ASTM F436 Type 1 / 1045 / 40Cr - washer profile with central bore
ASTM F436 Hardened WashersHardened washer pairing for structural bolt assemblies.
Heavy Structural Hex Head Bolts (ASTM A325 / A490) - 8.8 / 10.9 / 12.9 / A325 / A490 - 35CrMo / 42CrMo / Alloy Steel - hex head with threaded shank
Heavy Structural Hex Head BoltsRelated structural bolt product for non-weathering steel assemblies.
ASTM A563 Structural Hex Nuts (ASTM F3125 ref) - Grade DH / Grade 10 equivalent - ASTM A563 Grade DH / 1045 / 35K - hex body with internal thread
ASTM A563 Structural Hex NutsRelated structural nut product for standard high-strength bolting packages.
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Manufacturing

Manufacturing & Quality Control

Manufacturing CapabilityQuality Control
Hot forging or machining selected by nut size and gradeWeathering steel chemistry and heat number verification
Thread tapping for metric or UNC heavy hex nut threadsGO / NO-GO thread gauge, across-flats and height inspection
Unplated finish control for weathering compatibilitySurface and marking inspection by lot
Matched bolt-nut-washer assembly supplyProof load, hardness or rotational capacity support tests arranged when specified
Lot-based packaging for bridge projectsMTC, CoC and inspection report prepared on request
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FAQ

Common Questions Before RFQ

What is ASTM A563 Grade C3?

ASTM A563 Grade C3 is a weathering steel heavy hex nut grade used for atmospheric corrosion compatibility with weathering steel structural bolt assemblies.

What is the difference between C3 and DH3 nuts?

Both are weathering steel nut grades, but DH3 is a higher-strength heavy hex nut grade used where the structural bolting specification requires it.

Why are weathering steel nuts unplated?

They are often supplied unplated so the nut and weathering steel bolt assembly can develop compatible patina behavior. Coating restrictions should follow the project specification.

What sizes are commonly requested?

Common RFQ sizes include M16, M20, M22, M24, M30, 3/4 in, 7/8 in and 1 in heavy hex nuts. Final thread and grade should match the bolt assembly.

Can these nuts be supplied with bolts and washers?

Yes. Weathering heavy hex nuts can be supplied with compatible structural bolts and hardened washers as a complete bolting package.

Need ASTM A563 C3 / DH3 weathering steel nuts?

Send your nut grade, size, thread, matching bolt standard, washer requirement, quantity and certificate needs. Our team can quote weathering steel heavy hex nuts for bridge and exposed infrastructure projects.

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