High-strength structural bolts, nuts, washers, and anchor rod for steel-frame buildings, bridges, and heavy infrastructure. F3125 (A325 / A490), TC bolts, and F1554 — galvanized or plain, with full traceability on every shipment.
F3125 quenched-and-tempered structural bolts at 120 ksi (A325) and 150 ksi (A490) — the standard fasteners for steel-to-steel connections.
Bolt, nut, and washer shipped together as matched kits. Lot-by-lot rotational-capacity testing per F3125 Annex A2 on every shipment.
Hot-dip galvanized, mechanically galvanized, weathering Type 3, or plain finish — matched coatings across the bolt, nut, and washer.
MTRs and heat / lot traceability on every shipment. Domestic-melt and Buy America documentation available for DOT and bridge work.
Structural Fasteners is the family of high-strength bolts, heavy hex nuts, hardened washers, and anchor rod that show up on bolted steel connections — beam-to-column, splice plates, base plates, bridge girders, moment frames, and braces.
Spec'd through the F3125 umbrella standard (which now consolidates A325, A490, F1852, and F2280), and detailed at the joint level by the RCSC's Specification for Structural Joints. Stocked in plain, mechanically galvanized, and hot-dip galvanized — assembled and tested as bolt / nut / washer kits.Looking for foundation anchors, stud bolts, or general industrial hex? See cross-links at the bottom.
The full bolted joint — bolts, nuts, washers, and anchor rod — stocked deep and shipped together as tested assemblies.
The workhorse structural bolt — short, fully-threaded heavy hex pattern for steel-to-steel connections. Plain or galvanized.
Splined-end bolts that snap off at proper pretension. Faster, more consistent installation on slip-critical joints. Pre-assembled with nut and washer.
A563 Grade DH heavy hex matched to A325 and A490 structural bolts. Coatings matched to bolt — galv on galv, plain on plain.
Through-hardened structural washers for the bolt head and / or nut side of high-strength joints. Type 1 plain, Type 3 weathering.
Load-indicating washers (DTIs / "squirters") that compress visibly when the bolt reaches pretension. Inspector-friendly verification.
Headed, bent, and straight anchor rod for column bases and embed plates. Cut to length, with matching nuts and plate washers.
Structural connections are governed by F3125 for the bolts themselves and the RCSC Specification for the joint. Below is how we organize the specs we work in most often — if your detail calls something we haven't listed, ask.
The F3125 umbrella consolidates the four legacy structural bolt standards. Same product names you've always used — A325, A490, F1852, F2280 — now grades within F3125.
Medium-carbon, quenched and tempered heavy hex structural bolt — 120 ksi tensile up through 1″, 105 ksi above. Type 1 is plain or galvanized; Type 3 is weathering steel for unpainted exposed connections (think bridges, parking decks).
Alloy steel, quenched and tempered — 150 ksi tensile. Used where geometry or capacity calls for the higher-strength fastener. A490 must not be hot-dip galvanized; if you need a corrosion-resistant 150 ksi assembly, talk to us about alternatives.
Tension-control (TC / twist-off) bolts — A325 equivalent at F1852 (120 ksi), A490 equivalent at F2280 (150 ksi). Splined end snaps off at proper pretension. Shipped pre-assembled with nut and washer; lubricant pre-applied.
F1554 covers anchor rod for cast-in-place foundations — column bases, equipment skids, embed plates, and signpost foundations.
Mild carbon, weldable anchor rod — the default for low-to-moderate column loads, sign and light pole bases, and most non-seismic building anchorages. Available headed, bent (J / L), or straight with nut and plate washer.
Higher-strength carbon steel anchor rod with controlled chemistry. Spec the supplemental S1 requirement when the rod will be welded — common for tied-in column bases and bridge anchorages.
Quenched and tempered alloy anchor rod for high-uplift, seismic, and heavy-equipment anchorages. Wpd (weldable) supplement available; verify hydrogen-embrittlement procedures if hot-dip galvanizing.
The companion hardware that the joint won't perform without. We ship matched assemblies — bolt, nut, and washer from compatible heat lots, tagged together.
Carbon & alloy heavy hex nut. Grade DH (Type 1) for plain and galvanized A325 / A490; Grade DH3 (Type 3) for weathering steel. Coatings always matched to the bolt.
Through-hardened flat washer used under turned element when geometry calls for one — slotted holes, oversized holes, or A490 assemblies. Clipped pattern available where edge clearance is tight.
Direct-tension indicator — load-indicating washer with raised protrusions that compress at proper pretension. Squirter (HRC) variant ejects orange silicone for visual confirmation. Pairs with installer-friendly inspection.
The RCSC Specification recognizes three joint types — and the right pretension method depends on which one you're detailing. Snug-tight is fine for most bearing joints; pretensioned and slip-critical require verified installation.
The most common joint. Bolts brought to the snug-tight condition — full effort of an ironworker on an ordinary spud wrench, or a few hits of an impact. Adequate for static, non-fatigue, non-A490 conditions.
Bolt is installed to a verified minimum pretension (~70% of tensile strength). Required for fatigue-loaded connections, dynamic load reversal, A490 in tension applications, and long slip-resistant connections.
Same pretension as a pretensioned joint, plus a verified faying-surface condition (Class A, B, or C). Required where slip would be a serviceability or fatigue concern — bridge splices, crane runways, oversized / slotted holes.
Plain bolts inside a heated building. Hot-dip galvanized A325 on the bridge deck. Weathering Type 3 on the unpainted plate girder. Pick the right finish up front — re-coating high-strength bolts in the field isn't a thing.
Talk through finish optionsStructural bolts are inspected hardware. Every assembly we ship is traceable to heat and lot, with the documentation a structural inspector or DOT engineer expects to see.
MTRs / Mill Test Certificates tied to the heat and lot on every shipment. Mechanical & chemistry per F3125, A563, F436.
Lot-by-lot rotational-capacity test on assembled bolt / nut / washer kits per F3125 Annex A2. Documents the assembly's behavior under installation tension.
Domestic-melt / domestic-pour material with full state-DOT documentation. Common asks: Caltrans, AASHTO, Buy America bridge work — flag it on the RFQ.
F959 calibration test results and F1852 / F2280 lubrication and elongation test data shipped with the kits for the inspector's file.
Structural Fasteners is the steel-frame bolted-joint world. If your project lives one step over, start here instead.
Send the structural drawing, the bolt schedule, or the shop's BOM. A bolt specialist will come back with priced, packaged-per-connection kits — usually inside 24 hours.
From a single heavy hex kit to a full bridge-deck package with RoCap, DTI test data, and Buy America documentation — we've shipped the package before.