Product Description
4-40 UNC A2 Stainless Countersunk Phillips Machine Screws
4-40 UNC countersunk Phillips machine screws manufactured from A2 stainless steel. The flat countersunk head fits flush within a correctly prepared countersink.
Key Features
- 4-40 UNC thread
- 40 threads per inch
- A2 stainless steel
- Countersunk flat head
- Phillips cross-recessed drive
- Approximately 0.19 inch head diameter
- Available in packs from 5 to 1,000
Available Lengths
3/16", 1/4", 3/8" and 5/8".
Length is measured over the complete screw, including the countersunk head.
Standards
ASME B18.6.3:2024 provides the dimensional reference for inch-series countersunk Phillips machine screws.
BS 1580-3:2007 covers the 4-40 UNC thread form and tolerances for Unified threads below 1/4 inch. No direct British head standard has been verified.
Useful Links
- 2-56 UNC A2 countersunk Phillips machine screws
- 1/4 inch UNC A2 countersunk Phillips machine screws
- 4-40 UNC A2 countersunk slotted machine screws
- View all machine screws
Confirm that the mating nut or tapped hole has a 4-40 UNC thread before installation.
