Precision CNC Machined Pins & Dowels

For standard alignment applications, specify m6 tolerance for the pin diameter (typically +0.006/+0.002mm for sizes up to 10mm). This provides a reliable press fit into H7 reamed holes. For precision applications requiring tighter control, h6 tolerance (+0.004/0mm) can be achieved through precision grinding. The tighter the tolerance, the more consistent your press fit will be across all pins.

Solid dowel pins are precision ground cylindrical pins that require reamed holes for press-fit installation, providing the most accurate alignment. Spring pins (roll pins) are slotted tubular pins that compress during installation, allowing them to fit standard drilled holes without reaming. Solid dowels offer superior accuracy and strength, while spring pins provide easier installation/removal and accommodate slight hole size variations. Choose solid dowels for precision alignment, spring pins for easier assembly.

Hardened dowel pins (HRC 58-62) are recommended for high-load applications, repeated assembly/disassembly, or when mating with hardened surfaces. They resist wear and deformation better but are more brittle. Unhardened pins (HRC 20-30) are suitable for soft materials like aluminum or plastic, lower loads, and one-time assemblies. They're less likely to crack during installation but may deform under high loads. For critical aerospace or high-stress applications, always specify hardened pins.

A general rule is 0.005-0.015mm interference for steel-to-steel joints for pins under 10mm diameter. For larger pins, use 0.0005-0.0015mm per mm of diameter. Reduce interference by 30-50% for aluminum housings to prevent distortion. Factors affecting press fit include: material hardness (harder materials need less interference), wall thickness (thin walls need less interference), temperature (account for thermal expansion), and whether the pin is hardened. We can calculate optimal interference for your specific application.

Yes, we manufacture pins to military specifications (MS, NAS, AN) and aerospace standards including clevis pins (MS20392, AN392), cotter pins (MS24665, AN380), and precision dowel pins per AS8879. We provide complete documentation including AS9102 First Article Inspection Reports, material certifications with full traceability, dimensional inspection reports, and hardness test data. Our AS9100D certification ensures compliance with aerospace quality requirements.

Lead times vary based on complexity and quantity. Standard solid dowel pins from stock materials typically take 1-2 weeks including grinding and heat treatment if required. Custom pins with special features (grooves, heads, tapers) typically require 2-3 weeks. High-precision ground pins with tight tolerances may need an additional week for quality inspection. High-volume production orders are quoted based on quantity. Rush services available for urgent requirements.

Our centerless and cylindrical grinding processes routinely achieve Ra 0.2-0.4µm surface finish on dowel pins. This smooth finish ensures consistent press fits, reduces galling during installation, and provides excellent wear resistance. For applications requiring even finer finishes (such as precision bearings or sliding fits), we can achieve Ra 0.1µm through specialized grinding and lapping operations. Surface finish is verified using calibrated profilometers.

Yes, all custom pins include material test reports (MTR) with full traceability to heat lot. For aerospace applications, we provide AS9102 First Article Inspection Reports, Certificate of Conformance, dimensional inspection reports showing diameter measurements at multiple points along the length, hardness test data (surface and core for case-hardened pins), and surface finish verification. All documentation includes batch/lot traceability for complete accountability.