What the 1N6158A clamping voltage means for your rail
Its 35.8 V reverse standoff voltage lets it sit on a 28 V or 36 V nominal rail without conducting, and it clamps at 64.6 V maximum when hit with 23.2 A peak pulse current. That 64.6 V ceiling is the number your downstream DC/DC converter or load switch must survive.
Bidirectional channel and temperature range
A single bidirectional channel means the 1N6158A protects both polarities of an AC signal or a bipolar supply line with one device.
Active production and sourcing posture
The through-hole Axial package (B, Axial per the datasheet) is a standard footprint that mates with common PCB hole patterns and socket strips. Sourced per RFQ against your BOM quantity; no stock-holding claim here.