UNC Socket Head Cap Screws 1/4-20 alloy steel high strength bolts for automotive, engineering and workshop applications.

ASME B18.3 | High Strength | Coarse Thread | NZ

Strong, precise, and easy to work with.

These UNC socket head cap screws (1/4"-20) are designed for high-strength fastening where reliability and accessibility matter. Manufactured to ASME B18.3, they feature a compact socket (Allen) head, making them ideal for tight spaces and clean installations.

Made from high-strength alloy steel (comparable to metric 12.9), these fasteners deliver excellent tensile strength and durability. The UNC (coarse thread) provides faster installation and better performance in softer materials or general applications compared to fine thread bolts.

Strength where it counts. Control where you need it.

Why We Use Them in the Workshop

• High-strength alloy steel (12.9 equivalent)
• Socket head for tight access and clean installs
• UNC thread for versatility and easier engagement
• Strong and reliable under load
• Ideal for automotive and engineering work
• Consistent performance to ASME B18.3

Key Features

• Standard: ASME B18.3
• Material: Alloy steel
• Strength: Comparable to metric 12.9
• Finish: Plain (uncoated)
• Head Type: Socket head cap
• Drive Type: Internal hex (Allen)
• Thread Type: UNC (coarse thread)
• Thread Tolerance: ASME B1.1 Class 3A
• Thread Design: Full thread

Ideal For

• Automotive and mechanical assemblies
• Engineering and fabrication work
• Machinery and equipment
• Tight access fastening
• Workshop and trade use

Built for High-Strength Applications

These socket head cap screws NZ professionals rely on deliver precision, strength, and reliability — ideal for demanding applications.