Bolt Kit - 12pt 5pk 3/8-16 x 1.750

The ARP Bolt Kit – 12pt 5pk 3/8-16 x 1.750 (SKU ARP644-1750) is a precision fastener set engineered for high-performance engine and powertrain assembly where load-bearing reliability is non-negotiable. Each kit contains five chromoly bolts with black oxide finish, featuring a 7/16-inch 12-point head geometry that minimizes fastener rounding and ensures repeatable torque specifications across critical applications. The 3/8-16 thread pattern with 1.75-inch length makes these bolts ideal for engine block work, cylinder head assembly, and other demanding mechanical systems where material integrity directly impacts performance and safety.

Chromoly construction delivers superior tensile strength and fatigue resistance compared to standard steel fasteners, critical when managing repeated cycles of high heat and pressure. The 12-point head design offers greater surface contact area than traditional 6-point fasteners, reducing the risk of stripping during installation and removal—a practical consideration in high-vibration environments where fastener integrity determines system longevity. Black oxide coating provides baseline corrosion resistance and improves grip during installation. The universal fit across ARP's ecosystem means these bolts integrate seamlessly into existing fastener protocols and torque specifications used in motorsports, marine, and heavy-duty industrial applications.

Users working on engine builds, transmission assembly, or any application requiring repeatable, load-bearing fastening will find this five-pack configuration practical for prototype work, repair batches, or mixed-fastener assemblies where individual bolt replacement is necessary. The moderate length and thread pitch make these bolts suitable for mid-range bore depths without requiring specialized washers or spacers. ARP's reputation in high-performance fastening standards means these bolts are manufactured to consistent tolerances that support accurate torque wrench calibration and predictable clamp load.

Whether stocking a machine shop, completing an engine rebuild, or assembling a single critical component, this five-piece kit provides verified fastener quality without purchasing full case quantities. The combination of chromoly material, 12-point geometry, and black oxide finish represents ARP's baseline standard for applications where fastener failure risks downtime or safety compromise.