Why Use ARP 3/8-16 Bolts?

Cheap hardware:

• Flexes and stretches under load
• Strips threads or heads
• Doesn’t maintain torque

ARP Fixes That:

• High-strength alloy steel construction
• 12-point head design for better torque control and clearance
• Precision-machined threads for smooth engagement
• Black oxide finish for corrosion resistance

Translation: they hold torque, stay tight, and don’t fail when things get serious.

ARP 644-1500 three/eight”-sixteen x 1.500 UHL 12-Element Bolt Equipment – 5 Piece

Universal Fitment (3/8-16 Applications)

The 3/8-16 thread with 1.500” length is ideal for deeper mounting points and stacked components:

Common Uses:

• Engine brackets and accessories
• Intake manifold spacers or adapters
• Water pump and alternator mounting
• Transmission and bellhousing hardware
• Suspension and chassis components
• Custom fabrication setups

Popular Platforms:

• Small Block Chevy / Ford builds
• LS swap accessory mounting
• Classic muscle cars and hot rods
• Race and track applications

If your setup needs longer 3/8 hardware—this is exactly what you use.

ARP 644-1500 3/8-16 x 1.500 12 point bolt kit – Key Features

• Thread Size: 3/8″-16 (RH thread)
• Length: 1.500” under head
• Head Style: 12-point
• Material: High-strength ARP alloy steel
• Finish: Black oxide
• Quantity: 5 bolts per pack

Fasteners 12pt Bolts
Package deal Dimensions: 0.6 H x 2.7 L x 2.8 W (inches)
Package deal Weight: 0.3 kilos
Us of a of Starting place : United States

Performance Benefits

• Maintains consistent clamping force under load
• Prevents bolt stretch and thread damage
• Improves reliability in high-stress applications
• Supports performance and motorsport builds

No more wondering if your hardware is going to hold when it actually matters.

Installation Notes

• Use a 12-point socket
• Apply ARP Ultra-Torque or anti-seize depending on application
• Torque to appropriate specs for your setup

Why ARP?

Because even “basic bolts”:

• Fail when they’re cheap
• Matter when they’re under load
• Are easier to upgrade now than fix later

Final Verdict on the ARP 644-1500 3/8-16 x 1.500 12 point bolt kit

The ARP 644-1500 bolt kit is a go-to solution for longer 3/8-16 applications where strength, consistency, and reliability are critical.

Simple upgrade. Big difference when it counts.