Structural Heavy Hex Nuts
Structural heavy hex nuts are the high-grade nuts used with A325 and A490 structural bolts in steel-building, bridge, tower, and heavy-equipment connections. Eugene Fastener & Supply stocks both common specifications: A563 DH heavy hex nuts, the standard structural-bolting nut, and A194 Grade 2H heavy hex nuts, used on high-strength studs and high-temperature/pressure flange joints in piping and pressure vessels. Available plain and hot-dip galvanized to match your bolts.
Structural connections are code-driven, so the nut spec, grade, and finish must match the bolt assembly — galvanized nuts with galvanized bolts, and DH or 2H as the drawing calls out. We pair these with structural bolts and F436 structural washers so the full assembly ships from one source. By the piece or in bulk, with same-day shipping before 2pm Pacific.
Structural Heavy Hex Nuts — A563 DH & A194 2H
Need structural nuts matched to A325/A490 bolts, plain or galvanized, for a project?
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Include the diameter, spec (A563 DH or A194 2H), and finish (plain or HDG), plus quantity.
Structural Nut Specifications
- A563 DH Heavy Hex Nuts — the standard heavy hex nut for A325 and A490 structural bolting in steel construction. Available plain and hot-dip galvanized.
- A194 Grade 2H Heavy Hex Nuts — quenched-and-tempered nuts for high-strength studs (A193 B7) and high-temperature/pressure flange joints in piping and pressure vessels.
Matching Nuts to Structural Bolts
- A325 / A490 structural bolts: use A563 DH heavy hex nuts (DH is the standard grade for these assemblies).
- A193 B7 studs / flange bolting: use A194 2H heavy hex nuts.
- Finish must match: hot-dip galvanized nuts with galvanized bolts; plain with plain. Galvanized structural nuts are over-tapped and lubricated to spec.
- Complete the assembly: add F436 structural washers as the connection requires.
Structural Nut FAQ
What nut is used with A325 structural bolts?
A563 DH heavy hex nuts are the standard for A325 (and A490) structural bolting. They’re graded and dimensioned for structural-steel connections; on galvanized assemblies the nuts are hot-dip galvanized, over-tapped, and lubricated to match the bolts.
What’s the difference between A563 DH and A194 2H nuts?
A563 DH is the structural-bolting nut used with A325/A490 bolts in steel construction. A194 Grade 2H is a quenched-and-tempered nut for high-strength studs (such as A193 B7) and high-temperature/pressure flange joints in piping and pressure vessels. Both are heavy hex; use the one your spec calls out.
Do the nut and bolt finishes need to match?
Yes. Use hot-dip galvanized nuts with galvanized bolts and plain with plain. Galvanized structural nuts are over-tapped to clear the bolt’s zinc coating and lubricated to achieve proper tension — mixing finishes can cause assembly and tensioning problems.
What washers go with structural nuts?
F436 structural (hardened) washers, used under the turned element per the connection’s requirements. We stock F436 washers alongside the nuts and bolts so the full assembly ships together.
Can you supply matched A325 bolt, nut, and washer assemblies?
Yes — structural bolts, A563 DH nuts, and F436 washers from one source, plain or galvanized. Send the diameter, length, spec, and finish and we’ll quote the matched set.
Do you sell by the piece and cross-reference part numbers?
Both by the piece and in bulk. Send any spec or part number and we’ll match it, usually same business day, with pricing and lead time.
Why Buy Structural Nuts from Eugene Fastener
- A563 DH and A194 2H, plain and hot-dip galvanized.
- Matched assemblies — structural bolts, nuts, and F436 washers from one source.
- By the piece or in bulk, with cross-reference and spec help.
- Since 1969 — serving Pacific Northwest construction and industry for over 55 years.
Complete the structural connection: pair these nuts with structural bolts (A325/A490) and F436 structural washers. For general high-load joints see heavy hex nuts; for studs and rod, threaded rod. Browse all nut types or contact our sales team for matched assemblies and project pricing. Eugene Fastener & Supply — serving the Pacific Northwest since 1969.