The Hirose HRM-403S(40) is an SMA-style plug with a male pin centre contact, built for 50 Ohm systems. It carries a 12.4 GHz max frequency — that's the upper end of the SMA interface before mode propagation sets in, so keep the signal path below that ceiling for a clean launch. The gold-plated brass centre contact and PTFE dielectric hold consistent impedance through the mated pair, and the threaded coupling gives a vibration-resistant mate that doesn't rely on a snap ring. Rated for 1000 mating cycles. The gold-plated brass centre contact supports repeated field swaps without fretting corrosion. The stainless steel body resists corrosion in humid or salt-spray environments, and the flange mount with solder shield termination gives a solid ground reference at the panel.
Obsolete — sourcing the HRM-403S(40) when the channel is dry
The HRM-403S(40) is listed as Obsolete on the manufacturer's lifecycle record. That means Hirose has stopped production, and there is no official direct replacement part number on file. No official cross-reference exists from Hirose for this part. A parametric search for an SMA plug with the same 50 Ohm impedance, 12.4 GHz ceiling, panel-mount flange, and 1000-cycle life will turn up alternatives from other manufacturers, but none are a guaranteed drop-in without verifying the flange hole pattern and centre pin length against your existing board or panel layout.
Mating and termination — what fits and how it connects
Panel mount with a flange means you bolt it to a bulkhead or enclosure wall, and the threaded body provides the mechanical retention.