SS Countersunk Machine Screw (INCH)
Stainless steel countersunk machine screws (inch series) per ANSI/ASME B18.6.3 in A2-70 grade with coarse UNC thread. 82° conical head for flush mounting with Phillips cross-recessed drive from #6 to 3/8" range.
Specification
#
Standard
ANSI/ASME B18.6.3
Thread
Coarse (standard)
Material
Stainless Steel 304 (A2)
Grade
A2-70
Stock
In stock (304). Grade 316 available against bulk order
Dimension
#
Size (inch)
Thread Dia (min-max inch)
Pitch (TPI)
Length (inch)
Thread Length (inch)
#6
0.138-0.1380
32
1/4-1 1/2
Full thread
#10
0.190-0.1900
24
3/8-2
Full thread
1/4"
0.250-0.2500
20
1/2-3
Full thread
5/16"
0.3125-0.3125
18
5/8-3
Full thread
3/8"
0.375-0.3750
16
3/4-4
Full thread
- All dimensions in inches, tolerance +/- 0.001 inch. Additional dimensions available on request.
Benefits
#
Inch-series countersunk machine screws address flush-mounting requirements in equipment designed to imperial specifications, particularly in North American aerospace and defense applications. The 82° conical head nests into a matching countersunk recess, producing a smooth surface that eliminates snagging hazards and supports aerodynamic panel profiles. Stainless steel construction avoids the corrosion failures common with plated carbon steel fasteners in marine and outdoor environments where moisture and salt exposure degrade protective coatings. The Phillips drive enables controlled installation torque, and the conical geometry provides self-centering alignment during assembly. Imperial thread sizing maintains direct compatibility with existing tapped holes and legacy designs without requiring re-machining or metric conversion, reducing maintenance complexity and parts inventory for equipment operators.
Common Applications
#
Inch-series countersunk machine screws are used in imperial-designed assemblies where flush surface finish is required.
- Aerospace panels and structural assemblies
- Automotive body panels and trim components
- Electronics enclosures and equipment housings
- Marine deck hardware and hull fittings
- Industrial machinery guards and covers
- Precision instruments and measurement equipment
- Legacy equipment maintenance and repair
- North American market product assembly
Read Me
| Standard | ANSI/ASME B18.6.3 |
| Thread | Coarse (standard) |
| Material | Stainless Steel 304 (A2) |
| Grade | A2-70 |
| Stock | In stock (304). Grade 316 available against bulk order |
| Size (inch) | Thread Dia (min-max inch) | Pitch (TPI) | Length (inch) | Thread Length (inch) |
|---|---|---|---|---|
| #6 | 0.138-0.1380 | 32 | 1/4-1 1/2 | Full thread |
| #10 | 0.190-0.1900 | 24 | 3/8-2 | Full thread |
| 1/4" | 0.250-0.2500 | 20 | 1/2-3 | Full thread |
| 5/16" | 0.3125-0.3125 | 18 | 5/8-3 | Full thread |
| 3/8" | 0.375-0.3750 | 16 | 3/4-4 | Full thread |
