1/4-20 Button Head Socket Cap Screws Allen Bolts 18-8 Stainless All Lengths+Qty For Sale

1/4\"-20 Stainless Steel Button Head Socket Cap Screws 18-8 (304)

Internal Hex (Allen) • Multi-Length • UNC Coarse • Bulk

Description

Fastenio 1/4\"-20 button head socket cap screws in 18-8 (304) stainless steel. The low-profile button head sits ~25% lower than a standard socket head cap screw, giving a cleaner finished look while still accepting a 5/32\" hex (Allen) key for driving. ASME B18.3 dimensions throughout.

This listing covers 1/4\"-20 UNC Coarse only, in twenty lengths from 1/4\" through 5\", in pack quantities from 5 (sample) up to 2,500 (production bulk).

When to Use a Button Head SCS

• Low-profile look — when you want a clean rounded finish on the visible side without a flush countersink.
• Snag-free assemblies — the rounded crown reduces snag risk on equipment with frequent operator contact.
• Internal drive — hex (Allen) drive resists cam-out under high torque and works in tight clearances where a wrench wouldn\'t fit.
• Trade-off vs SHCS — lower clamp force capability than a standard socket head cap screw because the head is shorter. For maximum clamp load, see the cross-linked SHCS (Allen) listing.

Material

Grade: 18-8 Stainless Steel (Type 304 / A2-70 equivalent). Excellent corrosion resistance in atmospheric, freshwater, marine, and most chemical environments.

Finish: Plain (no plating). 18-8 forms a self-renewing passive oxide layer for natural corrosion protection.

Specification: ASME B18.3 button head socket cap screw dimensions.

How to Order

Select your variation by Length and Unit Quantity:

• Length — measured under-head to tip. 1/4\" is the shortest stock length; 5\" the longest.
• Drive: 5/32\" hex (Allen) key for all 1/4\"-20 button head SCS.
• Pack Quantity — 5 and 10 are sample/repair packs. 25–100 cover small projects. 250–2,500 are production-volume bulk.

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Need it faster? UPS 2nd Day Air and Next Day Air are available by request — message us with your ZIP code before purchase for a quote.

Need a larger quantity? Volume pricing is available beyond the listed pack sizes — message us with your target qty and we\'ll quote.

Bolt Specs at a Glance

Specifications below apply to every length variation. ASME B18.3 max dimensions; actual measurements may be slightly under (manufactured to tolerance).

Thread Size1/4-20 UNC (Coarse) Thread CoverageFully Threaded — all 20 length variations (1/4\" through 5\") Head StyleButton Head (low-profile dome) Head Diameter (A)0.437\" max Head Height (H)0.140\" max Drive TypeInternal Hex (Allen / Hex Socket) Drive Size5/32\" hex key Available Lengths1/4\" to 5\" — 20 sizes (select via Item Length dropdown) Material & GradeStainless Steel 18-8 (Type 304 / A2-70 equivalent) FinishPlain (passive oxide layer) StandardASME B18.3

Applications

• Marine — boat fittings, deck hardware (18-8 resists salt-water corrosion).
• HVAC — equipment mounts, condensation-exposed connections.
• Industrial — machinery assembly, equipment frames, custom fixtures.
• Automotive — trim, interior brackets, exposed assemblies where appearance matters.
• Construction — brackets, hardware, signage.
• Signs & Outdoor — signage, lighting fixtures, decorative metalwork.

Notes

• Torque: follow standard torque specs for 18-8 stainless 1/4\"-20 (typically ~76 in-lb dry). 18-8 is softer than alloy steel — do not over-torque.
• Galling prevention: use stainless-safe anti-seize for repeated assembly.
• Compared to SHCS: button head has lower clamp force capacity than a standard socket head cap screw of the same diameter. For high-clamp applications, see the cross-linked SHCS listing.
• Pair with: 1/4\"-20 finished hex nut + 1/4\" flat washer (cross-linked below) for through-bolting.

Related Fastenio Products

1/4-20 SS Socket Head Cap Screws

Standard SHCS (Allen) for higher clamp force.

View →

SS Finished Hex Nuts (Multi-Size)

1/4-20 hex nuts for through-bolting.

View →

SS Flat Washers 18-8

1/4\" flat washer for load distribution.

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