MS9390 Dowel Pin Buyers Guide: Specifications, Applications, and Selection

Introduction

MS9390 dowel pins are precision components crucial in aerospace, defense, and power generation industries. This guide provides a detailed overview of their specifications, applications, and selection criteria, drawing from authoritative sources and industry standards.

Technical Specifications

Drawing and Part Numbers

The MS9390 dowel pin is defined by the AS9390 drawing, which is maintained by SAE International [1]. Key points include:

• The current revision is AS9390D [1]
• Part numbers begin with MS9390, followed by a specific code for size and oversize options [1]
• It’s a “tab drawing,” containing multiple part numbers on a single document [1]

Dimensions and Tolerances

MS9390 dowel pins are manufactured to extremely tight tolerances:

• Diameter range: 0.0625″ to 0.6250″ [1]
• Length range: 0.250″ to 2.000″ [1]
• Diameter tolerance: ±0.00025″ across all sizes [1]
• Straightness: 0.0005″ Full Indicator Reading (FIR), Regardless of Feature Size (RFS) [1]
• Surface finish: 32 microinch Ra [1]

For each diameter/length combination, there are five options:

• Standard size
• Four oversize diameters: 0.002″, 0.005″, 0.010″, and 0.015″ [1]

Material and Manufacturing

• Material: A286 aged stainless steel [1]
• Manufacturing note: A286 is known for its challenging machinability due to high chrome and nickel content [2]

Special Features

• Oversize identification: All oversized parts, except for 0.0625″ and 0.09375″ nominal ODs, are marked on one end [1]
• End radius placement: For diameters above 0.09375″, the radius must be 0.090″-0.110″ and the radius origin must be 0.052” -0.072”from each end [1]

Compliance and Standards

MS9390 dowel pins must comply with several industry standards:

• AMS5732: Specification for A286 steel [3]
• AMS2700: Passivation of Corrosion Resistant Steels [4]
• ASME Y14.36M: Surface Texture Symbols [5]
• ASME B46.1: Surface Texture (Surface Roughness, Waviness, and Lay) [6]
• AS478: Identification Marking Methods [7]
• ANSI Y14.5M: Dimensioning and Tolerancing [8]

Applications

MS9390 dowel pins are primarily used in:

1. Aerospace: Particularly in aircraft engine assemblies and gas turbines [9]
2. Power Generation: Critical components in power plant turbine assemblies [10]
3. Defense: Precision alignment in various military equipment [11]

Selecting the Right MS9390 Dowel Pin

When choosing MS9390 dowel pins, consider:

1. Exact size requirements, including the potential need for oversized (overhaul) options
2. Application-specific demands (temperature, stress, corrosion resistance)
3. Compliance with relevant industry standards
4. Supplier capabilities in meeting tight tolerances and specifications

Conclusion

MS9390 dowel pins represent a high-precision solution to many of the critical needs of various industries. Their exacting specifications are designed to ensure optimal performance in demanding applications. When selecting these components, it’s crucial to consider all technical aspects and ensure compliance with relevant standards.

For more information, or to request a quote, please contact Russ Gordon at rgordon@horberg.com or 203.334.9444 ext. 121

Click to Download PDF of MS9390 Buyer’s Guide

References

[1] SAE International, “AS9390D – Pin, Dowel, Headless, Straight, A-286 CRES,” SAE Standards. [2] ASM International, “Machining of Stainless Steels,” ASM Handbook, Volume 16: Machining. [3] SAE International, “AMS5732 – Steel, Corrosion-Resistant, Bars, Wire, Forgings, and Tubing.” [4] SAE International, “AMS2700 – Passivation of Corrosion Resistant Steels.” [5] ASME, “Y14.36M – Surface Texture Symbols.” [6] ASME, “B46.1 – Surface Texture (Surface Roughness, Waviness, and Lay).” [7] SAE International, “AS478 – Identification Marking Methods.” [8] ASME, “Y14.5M – Dimensioning and Tolerancing.” [9] Federal Aviation Administration, “Aircraft Materials, Processes, and Hardware,” Aviation Maintenance Technician Handbook – General (FAA-H-8083-30A). [10] Electric Power Research Institute (EPRI), “Turbine-Generator Auxiliary Systems,” EPRI Technical Report. [11] U.S. Department of Defense, “Detail Specification: Pin, Straight, Headless (Dowel Pin),” MIL-DTL-16059.