1/4"-20 Grade 8 Indented Hex Flange Screws (Frame Bolts)

Heavy-Duty Grade 8 Alloy Steel with Black Phosphate & Oil Finish

Upgrade your fastening solution with our premium 1/4"-20 Grade 8 Indented Hex Flange Screws, also known as Frame Bolts or Hex Flange Screws. Manufactured from high-strength Grade 8 alloy steel, these bolts feature a built-in washer-style flange head and a durable black phosphate & oil finish for mild corrosion resistance and added lubrication during installation. Ideal for automotive frames, heavy equipment, and structural applications.

Key Features

• Diameter: 1/4 inch
• Thread Size: 1/4"-20 (20 TPI) – Coarse Thread
• Thread Length: Available in Full or Partial Thread (PT = Partial Thread)
• Wrench Size (Across Flats): 7/16 inch
• Head Style: Indented Hex Flange Head
• Finish: Black Phosphate & Oil for added lubrication and light corrosion resistance
• System of Measurement: Inch (Imperial / US)
• Material: Grade 8 Alloy Steel
• Specifications: Conforms to SAE J429 / ASME B18.2.1

Material & Finish Advantages

• High Strength: Grade 8 alloy steel is built for extreme load-bearing tasks and frame assembly.
• Flange Head: Built-in washer eliminates the need for a separate washer, distributes load evenly, and resists loosening.
• Black Phosphate & Oil Coating: Provides mild corrosion resistance and reduces galling during torque.

Common Applications

• Automotive Frame & Suspension Systems
• Heavy Equipment & Trailers
• Structural Steel Assembly
• Industrial Machinery Mounting

Why Choose Monster Bolts Flange Screws?

• Performance Rated: Trusted Grade 8 strength for high-stress environments.
• Flange Design Efficiency: Saves time and parts with built-in washer functionality.
• Bulk Options: Available in high-volume packaging to support industrial use. Buy Bulk Here
• Consistent Quality: Manufactured to meet strict tolerance and strength standards.

Installation Tips

• Use a torque wrench for critical applications to ensure correct preload.
• Inspect flange area for proper seating against surfaces to avoid over-tightening.
• Pair with matching Grade 8 flange nuts for optimal performance (sold separately).

Note: (PT) = Partial Thread. Be sure to verify your thread engagement needs before purchase.

Order Yours Today

Equip your next project with 1/4"-20 Grade 8 Indented Hex Flange Screws from Monster Bolts for superior strength and reliability. Ideal for professionals who demand dependable fasteners in demanding environments. Order now and enjoy fast U.S. shipping and excellent support.

✔️ Made from Grade 8 Alloy Steel

✔️ Black Phosphate & Oil Finish for Lubrication & Mild Protection

✔️ Ideal for Automotive Frame Applications

✔️ Bulk Quantity Available Here