Flange Button Head Socket Cap Screws
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.
Flange Button Head Socket Cap Screws FAQs
See the accordion below for quick answers on measuring length, head/flange dimensions, material choice, and washer replacement considerations.
It increases bearing area under the head to spread load and help protect thin or soft materials, often eliminating a separate washer.
From under the head to the tip (button/standard styles measure under head; flat heads are measured overall).
When you need low profile plus extra bearing area, or when you’d like to avoid loose washers in assembly.
Alloy steel black oxide for high strength in dry interiors; 18-8/304 for general corrosion resistance; 316 for marine/coastal or chemical exposure.
Yes, often, but depending on the load, very soft or delicate surfaces may still benefit from a dedicated washer or backing plate.
Follow size/material torque guidance and account for lubrication/finish. Button-style recesses are shallower than standard socket heads, avoid over-torque and recess rounding.
Yes, the flange helps spread load. Verify flange OD and consider a larger washer/flange or backup plate if pull-through is a risk.