Socket Head Cap Screws — Bulk Suppliers
75 vetted U.S. suppliers · 31 states
Socket head cap screws in bulk — mill-pack reel quantities, OEM-volume pricing — are sourced from a small set of fastener houses serving production manufacturing. Below is our live count of vetted U.S. suppliers, with one-click RFQs to multiple at once.
Geographic distribution
Where these suppliers are
Top 8 states by vetted-supplier density. 31 more across 23 additional states — listed below the chart.
Also covered
Alaska (2) · Delaware (2) · Colorado (2) · Massachusetts (2) · Georgia (2) · Connecticut (2) · Nevada (2) · Mississippi (2) · New Jersey (1) · Idaho (1) · North Dakota (1) · Arkansas (1) · Indiana (1) · New York (1) · Washington (1) · Utah (1) · Kentucky (1) · Louisiana (1) · Maryland (1) · Hawaii (1) · Vermont (1) · Nebraska (1) · Alabama (1)
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What socket head cap screws are
Socket head cap screws (SHCS, also called Allen-head bolts) are precision externally-threaded fasteners with an internal hex drive and cylindrical head — the standard machinery fastener where wrench clearance is limited or appearance matters. Spec'd per ASME B18.3 (inch) or ISO 4762 / DIN 912 (metric). Standard alloy is 1960-series alloy steel heat-treated to ~170 ksi tensile; stainless versions are 18-8 or 316. Bulk quantity = OEM-volume packaging, typically 100-1000 piece reels or cartons.
What to look for in a supplier
Match the grade to the load: alloy-steel SHCS (the default — heat-treated to 1960-series properties) for high-strength applications; 18-8 stainless for general corrosion service; 316 stainless for marine/chemical. For bulk OEM volume, ask about reel or carton minimums, lead time on common sizes, and whether the supplier maintains domestic stock or imports from Asia. Country-of-origin matters for defense and federal work; Buy America compliance is a separate qualification. Plating options for alloy-steel SHCS: black oxide (standard), zinc, zinc-nickel, and dry-film lube (e.g., Magni 565). For high-volume production, ask about consignment inventory and Kanban support.
FAQ
Common questions
What grade are standard socket head cap screws?
Alloy-steel SHCS are heat-treated to a property class equivalent to ASTM A574 — minimum 170 ksi tensile for sizes through 1", 160 ksi above. The head is typically marked with the manufacturer logo and indicates the high-strength alloy designation. Don't substitute Grade 5 hex bolts for SHCS — they're different strength.
What's the difference between socket head and button head cap screws?
Socket head has a cylindrical head with chamfered edges — used for general machinery fastening, especially where the screw recesses into a counterbore. Button head has a low-profile rounded head — used for cosmetic applications where head height matters but less strength is needed (typically lower tensile spec).
What's the typical bulk MOQ for SHCS?
Depends on size: ¼-20 × 1" might be 500-1000 piece reels; ½-13 × 2" might be 100-200 piece cartons. Most distributors stock standard sizes in mill-pack quantities and will quote OEM pricing at the carton-of-3 or carton-of-5 level. For very-high-volume work, factory-direct quotes can be arranged.
Are stainless SHCS strong enough for machinery work?
Generally no — 18-8 stainless tops out around 100 ksi tensile in fastener sizes, less than half the strength of alloy-steel SHCS. For load-bearing machinery applications, alloy-steel is the standard. Use stainless SHCS only where corrosion drives the choice and loads are low.
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