Stainless Steel Flat Head Socket Cap Screws
What are flat head socket cap screws? Flat head socket cap screws are stainless machine screws with a countersunk flat head and an internal hex drive that sit flush with the surface for a clean, high-strength finish. Made from stainless, they resist rust in wet and outdoor machinery where a flush socket screw is needed.
Flush fastening with socket screw strength
The flat head countersinks into an 82-degree or metric-angle chamfer so the top sits level with the surface, combining a clean flush finish with the high torque of an internal hex drive. That suits sliding parts, mating surfaces, and visible machinery where a protruding head would interfere. Match the countersink angle to the screw for full seating. In stainless, use anti-seize to prevent galling, and choose 316 for coastal machinery.
Why choose flat head socket cap screws
- Flush finish: countersinks level with the surface.
- Internal hex drive: high torque in a flush head.
- Corrosion resistance: holds up in wet and outdoor machinery.
- Grade options: 18-8 for general use, 316 for coastal exposure.
Common applications for flat head socket cap screws
- Sliding and mating surfaces
- Visible machinery needing a flush head
- Molds, dies, and fixtures
- Marine and coastal equipment (use 316)
For a low finished dome instead of flush, see stainless button head socket cap screws, and browse every head on the main socket head cap screws category.
Flat Head Socket Cap Screws FAQ
What countersink angle do these need?
Match the hole chamfer to the screw, commonly 82 degrees for inch and the specified angle for metric, so the head seats fully flush.
Are flat head socket screws as strong as standard?
The countersunk head is shallower, so they are somewhat less strong than a standard socket head but still take high torque via the hex drive.
Should I use 18-8 or 316?
18-8 suits most machinery. For coastal and marine equipment, choose 316 for the best corrosion resistance.