Titanium Bolt 5/16"-18 Bi-Hex/12point Flange Bolts, Professional wheel hub screws, by Tianswer

Aerospace-grade Ti-6Al-4V Grade 5 titanium 5/16″-18 UNC 12-point (bi-hex) flange bolts engineered for Harley-Davidson brake rotors, American V-Twin builds, and modular motorsport drag wheels.

Imperial 5/16″-18 UNC Architecture & 12-Point Flange

Precision CNC-machined to exacting imperial Unified Coarse specifications (5/16″ nominal diameter with 18 threads per inch), these high-strength fasteners feature an integrated 14.4mm diameter load-spreading flange and an aerospace 12-point (bi-hex) drive head. Driven with a standard 8mm (or 5/16″) 12-point socket, the 12-point head offers 30-degree indexing for superior ratchet clearance in tight hub cavities while completely eliminating head rounding under high torque preloads.

Unsprung & Peripheral Rotating Mass Reduction

Upgrading from heavy OEM chrome-plated steel hardware to Grade 5 titanium slashes fastener mass by over 45%. When installed on brake rotors, drive pulleys, or modular multi-piece wheel centers, removing peripheral rotating weight directly reduces wheel gyro inertia. This results in crisper turn-in handling on heavy V-Twin motorcycles, snappier launch acceleration in drag racing, and reduced suspension oscillation over uneven pavement.

Zero Corrosion vs. Flaking OEM Chrome

Factory steel bolts on American motorcycles and custom race wheels frequently suffer from chrome flaking, road-salt pitting, and severe rust around the hex drive. Certified Grade 5 (Ti-6Al-4V) titanium forms a permanent, self-healing oxide layer that is 100% immune to corrosion from brake dust, moisture, tire prep chemicals (such as TrackBite), and aggressive cleaners.

Key Applications

• Harley-Davidson & American V-Twin: Front and rear brake disc rotor mounting bolts (Dyna, Softail, Sportster, Touring, and custom choppers utilizing 5/16″-18 rotor mounts) and rear drive belt pulley hardware.
• Modular Drag Racing & Beadlock Wheels: 3-piece modular wheels (Weld Racing, Bogart, Billet Specialties), custom forged wheel centers, and off-road beadlock ring assemblies.
• Performance Marine & Offshore: Outboard motor mounting brackets, steering brackets, and marine transmission linkages requiring corrosion-proof high-tensile hardware.

Specifications & Dimensions

Material: Certified Aerospace Ti-6Al-4V (TC4) Titanium Alloy, Grade 5
Tensile Strength: >950–1050 MPa (Equivalent to Grade 8 imperial steel)
Thread Size: 5/16″ (approx. 7.94mm major diameter)
Thread Pitch / TPI: 18 Threads Per Inch (UNC Standard Coarse, ~1.411mm pitch)
Flange Head Diameter: 14.4mm
Flange Head Height: 9.3mm
Drive Type: 8mm (or 5/16″) 12-Point / Bi-Hex Socket
Available Lengths: 1.00″ (25.4mm) and 1.125″ (1-1/8″, 28.58mm)
Available Finishes: Natural Titanium, PVD Vacuum-Coated Gold, Rainbow, Burn Blue, PVD Deep Black

Installation & Torque Guidelines

Clean internal female hub threads thoroughly. For brake rotor and pulley installations, apply medium-strength blue thread locker (or anti-seize paste for wheel assembly) to the engagement threads. Tighten in a progressive criss-cross star pattern to factory service specifications (typically 20–24 lb-ft / 27–32 N·m for 5/16″-18 rotor bolts) using a calibrated manual torque wrench. For thread pitch identification and imperial-to-metric fastener guidelines, consult our Fastener Metrology & Thread Sizing Guide.

Price is for 1 bolt. (Always replace brake rotor and wheel hardware in complete sets).