Caleb Components supplies a wide range of Push on Fixings & Fasteners including:

M1465 Metric Push On Fasteners: https://springfasteners.co.uk/product-category/fixings-and-fasteners/push-on-fasteners-2/push-on-fastener-m1465/

N1465 Imperial Push On Fasteners: https://springfasteners.co.uk/product-category/fixings-and-fasteners/push-on-fasteners-2/push-on-fastener-imperial-n1465-range/

N1405 Imperial Self-Locking Rings: https://springfasteners.co.uk/product-category/fixings-and-fasteners/push-on-fasteners-2/n1405-imperial-self-locking-rings/

Starlock Washers (uncapped): https://springfasteners.co.uk/product-category/fixings-and-fasteners/push-on-fasteners-2/push-on-fasteners/