This 510 connector has an integrated one-piece core pin with a high heat resistant insulator and o-ring (up to 400C/752F) Just solder the wire to the core, reinstall the o-ring and insulator back on to pin and screw it all back together.
FDV V4 Low Profile 510 Connector
SKU: FDV-V45
$4.00Price
Basic set comes with body, insulator, core pin, solder tab, hex nut