Product Description
1/4" UNC A2 Stainless Steel Raised Countersunk Phillips Machine Screws
These 1/4" UNC raised countersunk Phillips machine screws are manufactured from A2 stainless steel and feature a 20 TPI Unified National Coarse thread. Available in 3/4" and 1" lengths, they are designed for use with matching 1/4"-20 UNC nuts or tapped holes.
The raised countersunk head, also known as an oval head, combines a tapered underside with a gently domed top. The countersunk section seats into a matching recess while the rounded top remains above the surface, providing a neat finish for panels, covers and visible fittings.
Key Features
- 1/4" UNC thread: imperial coarse thread with 20 threads per inch.
- A2 stainless steel: corrosion resistance for general indoor and outdoor applications.
- Raised countersunk head: combines countersunk seating with a decorative domed top.
- PH3 Phillips drive: suitable for a No. 3 Phillips screwdriver or bit.
- Imperial head dimensions: to ANSI B18.6.3.
- Choice of lengths: 3/4" and 1".
Product Specifications and Dimensions
| Thread Size | 1/4" UNC |
|---|---|
| Nominal Thread Diameter | 0.250" / 6.35mm |
| Threads Per Inch | 20 TPI |
| Thread Pitch Equivalent | 1.27mm |
| Material | A2 stainless steel |
| Head Style | Raised countersunk / oval head |
| Dimensional Standard | ANSI B18.6.3 |
| Drive Size | PH3 / No. 3 Phillips |
| Head Diameter | 0.442–0.477" / approximately 11.23–12.12mm |
| Head Height | 0.232" / approximately 5.89mm |
| Phillips Recess Diameter | 0.284" / approximately 7.21mm |
Head height includes the countersunk section and raised dome; it is not the height protruding above the fitted surface. Metric conversions are approximate. Dimensions are provided as a guide; please check with us if a measurement is critical to your application.
Available Sizes
| Thread Size | Threads Per Inch | Nominal Length | Metric Length Equivalent |
|---|---|---|---|
| 1/4" UNC | 20 TPI | 3/4" | 19.05mm |
| 1/4" UNC | 20 TPI | 1" | 25.4mm |
Typical Applications
- Panels and covers requiring a raised countersunk finish.
- Restoration and maintenance of equipment using UNC threads.
- Decorative fittings and trim with matching threaded fixings.
- General engineering assemblies requiring stainless steel machine screws.
Choosing and Fitting Your Screws
Check that the mating nut or tapped hole is 1/4"-20 UNC and choose a length that provides sufficient thread engagement. Ensure the countersink matches the screw head so the tapered underside seats correctly.
Use a PH3 Phillips screwdriver or bit, maintain firm engagement and tighten steadily. The domed top is designed to remain visible above the surface when installed.
Select your required length and pack quantity from the available options.
For help identifying threads, see our thread data guide. For material advice, read our A2 and A4 stainless steel guide.
