ARP 401-4704 BMW B48 M48 Custom Age 625+ Head Stud Kit 12-Point Undercut

The ARP 401-4704 is a premium head stud kit engineered specifically for BMW B48 4-cylinder engines. This kit features undercut studs manufactured from Custom Age 625+ material, ARP's advanced super-alloy that delivers superior fatigue cycle life, tensile strength, and toughness with complete resistance to atmospheric corrosion and oxidation.

Key Features:

• Custom Age 625+ material with 260,000-280,000 psi tensile strength
• 12-point nut design for precise torque application
• Undercut stud design for more consistent clamping force
• Thread rolled after heat-treat for superior fatigue strength
• Includes hardened parallel-ground washers
• Centerless ground for exceptional straightness and concentricity

ARP head studs provide vastly improved clamping force over OEM head bolts, helping to eliminate cylinder head movement and prevent head gasket failure—especially critical in boosted or high-performance applications. Each stud is cold-forged to ensure molecular integrity and heat-treated to exacting specifications. The undercut design equalizes stretch between studs for more consistent gasket compression and superior sealing reliability.