Standard Socket Head Cap Screws
What are Standard Socket Head Cap Screws?
Standard socket head cap screws (SHCS) are high-strength machine screws with a cylindrical head and a deep internal hex drive. The tall head provides generous bearing area and allows high installation torque in tight spaces, making SHCS a staple for precision assemblies, jigs, and machinery.
Why choose Standard Socket Head Cap Screws
- High clamp load — deep hex socket supports high tightening torque.
- Compact footprint — internal drive works where external hex heads won’t fit.
- Repeatable alignment — uniform head geometry for consistent preload.
- Versatile threading — available in coarse/fine inch and metric ISO threads.
Materials & finishes for Standard Socket Head Cap Screws
- Alloy steel black oxide — very high strength for dry interior environments.
- Stainless 18-8 / 304 — broad corrosion resistance for most applications.
- Stainless 316 — added resistance for marine/coastal or chloride exposure.
- Zinc-plated or coated steel — economical corrosion protection on select sizes.
How do I size and specify Standard Socket Head Cap Screws?
Order by diameter × thread × length (e.g., 1/4″-20 × 1-1/2″, 10-32 × 3/4″, M6-1.0 × 25 mm). Length is measured from under the head. Match UNC/UNF or metric ISO to the tapped component, and verify head diameter/height clearance in your design.
Standard SHCS vs other socket cap styles
- Standard vs button head — standard supports higher torque; button offers lower profile and wider bearing.
- Standard vs flat head — flat head sits flush in a countersink; torque capacity is limited by the countersink and head geometry.
- Standard vs low-profile — low-profile saves height at the cost of reduced drive depth/torque.
Common applications for Standard Socket Head Cap Screws
- Industrial machinery, automation, and motion systems
- Tooling, fixtures, and precision equipment
- Automotive, aerospace, and equipment assembly
- Structural brackets, guards, and tight-clearance joints
Installation tips for Standard Socket Head Cap Screws
- Use the correct hex key fully seated to prevent recess rounding.
- Apply specified torque for the size/material; consider threadlocker where vibration exists.
- Use washers or flanged components to protect surfaces and distribute load where needed.
- For stainless into aluminum, consider anti-seize to mitigate galling and galvanic effects.
Standard Socket Head Cap Screws FAQs
See the accordion below for quick answers on sizing, measuring length, torque, materials, and when to choose standard SHCS over button or flat heads.
A cylindrical head with a deep internal hex drive designed for high torque and compact installations.
From under the head to the end of the screw. (Flat heads are measured overall.)
Alloy steel (black oxide) for maximum strength in dry interiors; 18-8/304 for general corrosion resistance; 316 for marine/coastal or chloride exposure.
Coarse for quick assembly and softer materials; fine for better thread engagement and vibration resistance in hard materials.
Use washers or flanged components when you need more bearing area or to protect finished surfaces.
Follow size/material torque charts and account for lubrication/finish. Over-torque can strip threads or round the socket.
Yes, match threads carefully and consider anti-seize (especially with stainless) to reduce galling and galvanic corrosion.