D38999 Circular Connector Specs & Part Number Decoding Guide

When looking at rugged circular connectors for field deployment, engineers and procurement buyers always spend time going over basic electrical specs and deciphering part codes. Many run into confusion reading D38999-style connector model numbers, and missing these details can easily lead to wrong component picks.

This connector family comes with defined electrical parameters, including contact resistance, rated current and dielectric withstanding voltage. Its shielding structure cuts EMI interference effectively. Attenuation reaches minimum 85dB between 100MHz and 1GHz. From 1GHz to 10GHz, the minimum attenuation drops to 50dB. Insulation resistance keeps over 5000MΩ under normal working conditions. Shell bonding resistance is kept within narrow limits, to guarantee steady grounding.

Temperature tolerance varies across different grades. Class B works reliably from -65°C up to +175°C. E and F versions can run continuously at max 200°C. These connectors must pass a full set of tests: salt spray, high humidity and high altitude. They resist dampness, salt mist, mould and sand, which makes them suitable for tough outdoor and industrial sites.

Decoding the part number is often the tricky part for new purchasers. Every single letter and digit tells a different feature. Users can get connector type, shell category, shell size, plating type, insert arrangement, contact style, keying and termination method directly from the code.

One practical point worth noting: GJB599A JY series uses the same naming logic as MIL-DTL-38999. The only difference is the prefix code. Products under these two standards can swap with each other.

For projects requiring stronger heat resistance, fluorosilicone seal material is offered. Add suffix C1 at the end of the part number for this option. Full datasheets and technical references can be requested, so engineering teams can finish product assessment before ordering.