Low Profile Socket Head Cap Screws
What are low profile socket head cap screws?
Low profile socket head cap screws are machine screws with a shortened cylindrical head and an internal hex (Allen) drive. They deliver near-flush clearance where standard socket heads are too tall while still allowing controlled torque and a clean, finished look.
Why choose low profile socket head cap screws
- Clearance saving — reduced head height fits tight spaces, sliding components, and low-overhead covers.
- Compact drive — internal hex works where external hex bolts won’t fit.
- Clean aesthetics — sleek profile for visible hardware and panels.
- Versatile threading — available in UNC/UNF and metric ISO across common sizes.
Materials and finishes for low profile socket head cap screws
- Alloy steel black oxide — high strength for dry interior service (verify corrosion protection needs).
- Stainless steel 18-8 / 304 — broad corrosion resistance for most environments.
- Stainless steel 316 — added resistance for marine/coastal or chloride exposure.
- Zinc-plated steel — economical corrosion protection on select grades.
How do I size and specify low profile socket head cap screws?
Specify diameter × thread × length (e.g., 1/4″-20 × 3/4″, 10-32 × 1/2″, M6-1.0 × 16 mm). Length is measured from under the head. Confirm head diameter/height clearances and match UNC/UNF or metric ISO threads to the tapped component.
Low profile vs other socket cap styles
- Low profile vs standard socket head — saves height but has a shallower hex recess, so torque capacity is lower than standard SHCS.
- Low profile vs button head — both reduce height; button provides a rounded appearance and wider bearing area.
- Low profile vs flat head — flat head sits fully flush in a countersink; low profile sits above the surface and requires no countersink.
Common applications for low profile socket head cap screws
- Equipment guards, covers, and sliding panels with limited overhead space
- Electronics, instruments, and fixtures with tight clearance envelopes
- Automotive, robotics, and machinery where snag-resistant hardware is preferred
- Assemblies needing a clean look without countersinking
Installation tips for low profile socket head cap screws
- Use the correct hex key fully seated; shallow recesses are more sensitive to rounding.
- Apply the specified torque for size/material; consider threadlocker in vibration.
- Verify bearing area on soft materials; add a washer or flange component if needed.
- For stainless into aluminum, use anti-seize to mitigate galling and galvanic corrosion.
Low Profile Socket Head Cap Screws FAQs
See the accordion below for quick answers on measuring length, torque considerations with shallow sockets, material selection, and when to choose low profile over button or flat head styles.
A shortened cylindrical head with an internal hex drive that reduces installed height compared to a standard socket head.
From under the head to the tip (flat heads are measured overall).
When vertical clearance is limited and you still want a socket-drive fastener. Use standard SHCS when maximum torque capacity is required.
Use low profile for a cylindrical, compact look with smaller head OD; use button head for a rounded appearance and wider bearing area.
Black-oxide alloy for high strength indoors; 18-8/304 for general corrosion resistance; 316 for marine/coastal or chloride exposure.
Only if surface protection or added bearing area is needed, especially on soft materials.
Yes. The hex recess is shallower than standard socket heads; to prevent recess rounding, use the correct key, apply the specified torque, and avoid over-tightening.