Metallics Machine Screw 1/4-20 x 1/2" Round Head Combo Steel Zinc

Metallics Industries Machine Screw 1/4-20 x 1/2" Round Head Combo Steel Zinc

Professional Dual-Drive Fastener Solution

The Metallics Industries Machine Screw 1/4-20 x 1/2" Round Head Combo delivers exceptional versatility and reliability for electrical, plumbing, and HVAC applications. This steel zinc machine screw provides dependable fastening solutions designed for professional contractors, electricians, and industrial technicians, offering the proven quality and precision engineering that professionals trust from a leading manufacturer of electrical hardware and industrial fasteners.

Professional Features & Benefits

Dual-Drive Performance

• Combo Drive Design - Features both slotted and Phillips drive options in one head for maximum installation flexibility and tool compatibility
• Round Head Configuration - 0.443-0.472" head width provides optimal bearing surface and professional finished appearance
• Precision Threading - 1/4-20 thread specification ensures reliable engagement and holding power in threaded applications
• Steel Zinc Construction - AISI 1006-1022 steel with zinc finish delivers corrosion resistance and durability for demanding environments

Installation Versatility

• Driver Compatibility - #3 driver size accommodates standard professional tools for efficient installation
• Controlled Penetration - Phillips recess depth of 0.121-0.147" and slot depth of 0.082-0.109" provide secure driver engagement
• Professional Finish - Zinc coating provides corrosion protection while maintaining clean appearance for visible installations

Strength & Reliability

• High Tensile Strength - 60,000 psi minimum tensile strength ensures reliable performance under load
• Controlled Hardness - Rockwell B70-B100 hardness provides optimal balance of strength and workability

Technical Specifications

Thread Size: 1/4-20, Length: 1/2", Material: Steel Zinc (AISI 1006-1022), Finish: Zinc, Drive Type: Slotted/Phillips Combo, Head Type: Round, Head Width: 0.443-0.472", Head Height: 0.16-0.175", Driver Size: #3, Phillips Recess Depth: 0.121-0.147", Phillips Recess Diameter: 0.255-0.268", Slot Depth: 0.082-0.109", Slot Width: 0.064-0.075", Tensile Strength: 60,000 psi minimum, Hardness: Rockwell B70-B100, Pack Type: Jar, Weight: 1.01 lbs

Installation & Usage

1. Select appropriate driver tool - either slotted or Phillips based on installation preference and access requirements
2. Ensure threaded hole or nut is properly aligned and sized for 1/4-20 thread engagement
3. Insert screw and begin threading by hand to prevent cross-threading and ensure proper alignment
4. Use #3 driver size tool to tighten screw, taking advantage of combo drive flexibility for optimal access
5. Apply appropriate torque based on material and application requirements, monitoring for proper seating
6. Verify secure fastening and proper bearing surface contact for reliable long-term performance

Professional Applications

Ideal for:

• Electrical Installations - Panel mounting, junction box assembly, conduit support brackets, and electrical equipment fastening
• HVAC Systems - Ductwork connections, equipment mounting, control panel assembly, and ventilation component installation
• Plumbing Applications - Fixture mounting, pipe support systems, valve assembly, and plumbing equipment installation
• Equipment Assembly - Machine component fastening, control panel construction, and precision equipment mounting
• Industrial Maintenance - Equipment repair, component replacement, and facility maintenance applications
• Commercial Construction - Building system installation, infrastructure mounting, and professional construction projects
• Panel Box Installation - Electrical panel assembly, breaker mounting, and control system construction
• Mechanical Fastening - General purpose threaded fastening where dual-drive capability provides installation advantages

Steel Zinc Construction Advantage

The steel zinc construction provides excellent corrosion resistance for indoor and protected outdoor applications while maintaining the strength characteristics essential for reliable fastening. The zinc finish offers superior protection against moisture and environmental factors commonly encountered in electrical, plumbing, and HVAC installations, ensuring long-term performance and professional appearance.

Why Choose Metallics Industries Quality?

Metallics Industries' commitment to precision manufacturing ensures consistent thread quality, accurate dimensions, and reliable performance. Since 1985, Metallics was the first fastener company in America to offer a full line of combo drive fasteners, demonstrating our innovation leadership and dedication to providing contractors and industrial professionals with superior fastening solutions. Our comprehensive quality control, premium materials, and engineering excellence deliver the trusted performance that electrical, plumbing, HVAC, and construction professionals depend on for critical applications.