Hex Bolts — Bulk Suppliers
44 vetted U.S. suppliers · 16 states
Hex bolts in bulk — mill-pack carton volume, distributor-grade pricing — are sourced from a specific subset of fastener houses serving production manufacturing, contractor distribution, and OEM assembly. Below is our live count of vetted U.S. suppliers carrying them, with state distribution and a one-click RFQ flow.
Geographic distribution
Where these suppliers are
Top 8 states by vetted-supplier density. 8 more across 8 additional states — listed below the chart.
Also covered
New Jersey (1) · Oregon (1) · Missouri (1) · Pennsylvania (1) · Virginia (1) · Georgia (1) · Michigan (1) · Alabama (1)
See the list
Want to see all 44 suppliers?
Run the search and we'll show you who they are. Send branded RFQs to as many as you want in a single email — your search is pre-loaded.
What hex bolts are
Hex bolts (also called hex machine bolts or hex cap screws) are externally-threaded fasteners with a hexagonal head, designed for wrench installation. ASME B18.2.1 covers inch sizes; DIN 933 / ISO 4014 cover metric. Common materials: carbon steel (Grade 2, Grade 5, Grade 8), stainless (18-8 / 316), and alloy steels for higher-strength variants. Standard finishes include plain (uncoated), zinc-plated, hot-dip galvanized, and black oxide. Bulk = mill-pack carton volume, typically 50-500 pieces per box depending on diameter.
What to look for in a supplier
Match the grade to the load: Grade 2 for low-stress work, Grade 5 (most common general-purpose), Grade 8 (high-strength). For corrosion environments use 18-8 or 316 stainless instead. Confirm spec: ASME B18.2.1 / SAE J429 for inch grades, DIN/ISO for metric. For high-volume wholesale, ask about MOQ (mill-pack vs. break-pack), domestic-vs-imported sourcing (matters for Buy America and DFARS work), and stocked finishes. Hot-dip galvanized has thicker zinc and requires nut overtapping; mechanically galvanized is thinner with tighter dimensional fit. Traceability documentation (mill certs, heat-lot records) matters for federal, defense, and infrastructure contracting.
FAQ
Common questions
What's the difference between Grade 5 and Grade 8 hex bolts?
Grade 5 has a minimum tensile of 120 ksi (medium carbon, quenched and tempered) — covers most general industrial applications. Grade 8 is 150 ksi (alloy steel, quenched and tempered) for higher-stress applications like equipment mounting and load-bearing assemblies. Grade 8 is more expensive and slightly more brittle. Choose based on the load and bolted-joint analysis.
What's the difference between a hex bolt and a hex cap screw?
Technically a hex cap screw has tighter dimensional tolerance and a precision-machined washer face under the head; a hex bolt has looser tolerance and a rougher surface. In practice, U.S. distributors use the terms interchangeably for general work. ASME B18.2.1 covers both; the spec doesn't meaningfully distinguish them in modern usage.
What's a typical bulk MOQ on hex bolts?
Varies by diameter: ¼-20 mill-pack is typically 100-200 pieces; ½-13 might be 50-100; ¾-10 might be 25-50. Most distributors break carton on a case-of-1 basis at retail price; wholesale pricing kicks in at mill-pack quantity. Ask for break-point pricing per diameter.
Should I use zinc-plated or hot-dip galvanized hex bolts outdoors?
Depends on environment. Zinc-plated handles indoor and protected outdoor service for several years. Hot-dip galvanized (HDG) has thicker zinc — decades of outdoor corrosion protection, but adds dimensional buildup that requires nut overtapping. For pressure-treated lumber, marine, or buried service, HDG or stainless (304 / 316) is the right call.
Ready to see the suppliers?
44 vetted U.S. suppliers waiting in your search.