Titanium Crank Bolts Manufacturers & Factory serving the Zagreb Market

For critical crank bolts, bottom bracket fasteners, and drivetrain shafts subjected to intense rotational shear and cyclic bending stresses, Grade 5 Ti-6Al-4V (also designated as TC4) is our standard recommendation. Grade 5 delivers a tensile yield strength of 828 MPa and an ultimate tensile strength exceeding 895–1050 MPa. In contrast, commercially pure titanium (Grade 2) possesses approximately 345 MPa tensile strength, which is suitable for decorative or non-structural fluid fittings but inadequate for primary dynamic drivetrain torque loads.

Titanium has a natural tendency to gall when torqued dry against matching metal threads. We mitigate this through several engineering protocols: first, threads are precision rolled and polished to a mirror finish (Ra < 0.4 µm) to eliminate microscopic surface asperities; second, we offer surface treatments such as PVD Titanium Nitride (TiN), Diamond-Like Carbon (DLC), or micro-arc oxidation; third, we specify the application of an anti-seize lubricant containing molybdenum disulfide or copper paste during installation, which stabilizes the torque-friction coefficient and protects both fastener and mating threads.

For prototypes, samples, or urgent racing batches, we utilize air express couriers (DHL, FedEx, UPS) with transit times typically between 4 to 7 business days directly to Zagreb (Franjo Tuđman Airport customs terminal). For larger commercial production runs, we coordinate air cargo or sea-rail logistics terminating at the Port of Rijeka or Zagreb logistics hubs under standard Incoterms (EXW, FOB, CIF, or DDP). We furnish all necessary documentation, including commercial invoices, packing lists with Harmonized System (HS) codes, and Certificates of Origin to facilitate smooth Croatian customs clearance.

For custom CNC machined crank bolts engineered from proprietary 2D/3D customer drawings, our standard production MOQ is generally between 100 to 300 pieces, depending on part complexity and tooling setup. However, to support your design validation and prototype assembly testing, we offer initial sample runs (5 to 10 units) accompanied by first-article inspection reports before releasing the job for full volume manufacturing.

Every production batch is accompanied by comprehensive quality verification dossiers. Upon request, we provide EN 10204 3.1 Mill Test Certificates showing the chemical composition and mechanical properties of the raw titanium, optical CMM dimensional inspection reports, and thread pitch gauge verification logs. This thorough traceability simplifies your incoming goods inspection and satisfies downstream ISO 9001 and automotive audit requirements.