What are flange button head socket cap screws?
Flange button head socket cap screws are machine screws with a low, rounded head, an internal hex drive, and an integrated flange under the head. The flange increases bearing area to spread load and help protect softer materials or thin sheet without a separate washer.
Why choose flange button head socket cap screws
- Built-in load distribution — the flange acts like a captive washer to reduce surface pressure and pull-through risk.
- Low-profile aesthetics — smooth, rounded head looks finished and reduces snagging.
- Compact drive — internal hex (Allen) fits tight spaces and concealed hardware designs.
- Versatile threading — offered in UNC/UNF and metric ISO across common sizes.
Materials and finishes for flange button head socket cap screws
- Alloy steel black oxide — high strength for dry interior service.
- Stainless steel 18-8 / 304 — dependable corrosion resistance for most environments.
- Stainless steel 316 — enhanced resistance for marine/coastal or chloride exposure.
- Zinc-plated steel — economical corrosion protection on select grades.
How do I size and specify flange button head socket cap screws?
Specify diameter × thread × length (e.g., 1/4″-20 × 1″, 10-32 × 3/4″, M6-1.0 × 20 mm). Length is measured from under the head. Confirm head diameter/height and flange OD clearances, and match UNC/UNF or metric ISO to the tapped component.
Common applications for flange button head socket cap screws
- Panels, guards, covers, and enclosures where washers are undesirable
- Thin sheet, plastics, and composites needing greater bearing area
- Electronics, fixtures, furniture, and decorative metalwork
- Automation and light machinery where low profile is preferred
Flange button vs other socket cap styles
- Flange button vs button head — same low profile; flange version adds built-in bearing to reduce the need for a washer.
- Flange button vs standard socket head — standard supports higher torque with a deeper socket; flange button emphasizes appearance and bearing area.
- Flange button vs flat head — flat head sits flush in a countersink; flange button sits above the surface and does not require countersinking.
Installation tips for flange button head socket cap screws
- Seat the hex key fully and tighten to the specified torque for size/material.
- Verify that the flange OD clears adjacent features and doesn’t interfere with slots or edges.
- Use threadlocker in vibration-prone assemblies to preserve preload.
- For stainless in aluminum or other dissimilar metals, consider anti-seize to mitigate galling and galvanic corrosion.