S-91771A851 4-48 x 3/16" ASME B18.6.3 Stainless Steel Phillips Flat Head Screws
Stainless Steel Phillips Flat Head Screws
Image may differ from product. See technical specification for details.
Basic Information
Head Parameters
Dimensions
Thread Parameters
Tip & Drive Parameters
Material & Strength
Temperature & Environment
- Fast delivery
- Enjoy discounts on bulk purchases
- Secure Payment
- Fast Global Shipping
Key Features & Benefits at a Glance
- Superior corrosion resistance with passivated 18-8 stainless steel construction for extended service life in harsh environments
- Exceptional mechanical strength with 70,000 psi tensile strength and Rockwell B80 hardness for reliable load-bearing performance
- Precision thread engagement through Class 2A thread fit and UNF fine threads ensuring vibration-resistant connections
- Optimized flush mounting with undercut flat head design and 82° countersink angle for seamless surface integration
- Enhanced drive stability with Phillips #1 drive system preventing cam-out during high-torque installation
- Full-threaded reliability providing consistent clamping force across the entire 3/16" length
- Regulatory compliance assurance meeting ASME B18.6.3 standards and environmental regulations including RoHS 3 and REACH
Professional Applications & Engineering Value
These 4-48 UNF flat head screws deliver critical performance advantages for precision assemblies requiring flush surface mounting and reliable fastening in demanding conditions. The passivated 18-8 stainless steel construction provides excellent resistance to corrosion and chemical exposure, making these Phillips drive screws ideal for electronics enclosures, instrumentation panels, and aerospace components where material integrity is paramount. The undercut flat head profile ensures proper seating in countersunk holes while the fine UNF threads maintain secure connections in vibration-prone applications. With full threading along the 3/16" length, these screws distribute clamping force evenly, preventing joint loosening in critical industrial assemblies.
Specification Summary & Compliance
Manufactured to precise dimensional standards with Class 2A thread fit tolerance and UNF fine thread specifications. These flat head screws comply with ASME B18.6.3 mechanical and dimensional requirements, ensuring interchangeability and reliability. Environmental compliance is verified through RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming the absence of restricted substances. The 82° countersink angle and undercut head design meet industry standards for flush mounting applications in precision engineering.
