There are several types of locating pins for fixtures, each designed for specific positioning requirements. Dowel locating pins are cylindrical and commonly used to constrain components in both X and Y axes, providing rigid and repeatable positioning. Conical locating pins, featuring a tapered geometry, offer self-centering functionality and are often preferred in automated fixtures and high-speed assembly lines.
Diamond locating pins, identifiable by their two-flat profile, are typically used in combination with round pins to control position in one axis while allowing freedom in the other. This design helps compensate for thermal expansion, machining tolerances, and minor part distortions, reducing the risk of fixture binding or over-constraint. Selecting the correct locating pin type is critical for robust fixture design and long-term dimensional stability.
When selecting a locating pin, several technical parameters must be evaluated. Locating pin material plays a major role—tool steel is widely used for general-purpose fixtures, stainless steel is suitable for corrosive or washdown environments, and hardened or heat-treated steel provides superior wear resistance for high-cycle applications.
Locating pin tolerance directly affects positioning accuracy; tighter tolerances improve repeatability but require precise hole preparation. Surface finish also influences performance—polished or ground surfaces reduce friction and wear, while surface treatments such as black oxide, hard chrome, or nitriding enhance corrosion resistance and service life. Engineers often perform locating pin design calculations to verify load capacity, shear strength, and positional accuracy over extended production runs.
Locating pins are used extensively across industries such as automotive, aerospace, electronics, and general industrial automation. In CNC machining, they accurately position workpieces on pallets and fixtures. In mold making, they align cores and cavities with high repeatability. In assembly fixtures, locating pins ensure proper part orientation before fastening, reducing assembly errors and cycle time. During inspection and quality control, they act as datum references for precise dimensional verification.
Routine inspection is essential to maintain accuracy and extend the service life of locating pins. Check for wear, burrs, deformation, or corrosion that could affect fit and alignment. Clean pins regularly to remove chips, dust, or residue. Pins showing excessive wear should be replaced promptly to prevent fixture inaccuracies, scrap generation, or equipment downtime.
MISUMI offers a comprehensive range of locating pins engineered for precision fixture applications. Available in multiple diameters, lengths, materials, and tolerance classes, MISUMI locating pins support both standard and custom fixture designs. With fast delivery, no minimum order quantity, and free CAD downloads, MISUMI simplifies sourcing high-quality dowel pins, diamond pins, and conical locating pins for demanding manufacturing environments.