UNF Hex Bolt 1/4-28 Grade 5 Zinc Plated

ASME B18.2.1 | Fine Thread | High Strength | NZ

Precision fit. Proper hold.

These UNF hex bolts 1/4"-28 x 1" are manufactured to ASME B18.2.1 standard and designed for applications requiring fine thread engagement and higher clamping accuracy. The UNF (fine thread) profile provides increased resistance to loosening and improved load distribution compared to coarse thread fasteners.

Made from Grade 5 steel and finished with zinc plating and blue passivation (A2K), these bolts deliver reliable strength and corrosion resistance for automotive, machinery, and fabrication work.

Tighter threads. Stronger hold. Built for precision.

Why We Use Them in the Workshop

• UNF fine thread for improved clamping and vibration resistance
• Grade 5 steel for high-strength performance
• Better load distribution than coarse thread bolts
• Zinc plated for corrosion resistance
• Reliable for automotive and engineering applications
• Consistent quality to ASME standard

Key Features

• Size: 1/4"-28 x 1"
• Standard: ASME B18.2.1
• Material: Steel
• Grade: GR5
• Finish: Zinc plated, blue passivated (A2K)
• Head Type: Hexagon
• Thread Type: UNF (fine thread)
• Thread Design: Full thread
• RoHS Compliant: Yes

Ideal For

• Automotive applications
• Engine and mechanical assemblies
• Machinery and equipment
• Precision fastening applications
• Workshop and fabrication use

Built for Precision Fastening

These UNF bolts NZ workshops rely on deliver accurate fit, strong clamping force, and dependable performance in demanding applications.