I used to do HVAC service. Around here are a number of heat pump systems using an electric furnace as an air handler/ emergency (auxiliary) heat. Most all use the same 1/4" flag/ spade push on terminals as the bulkhead connector. An electric element is nominally 20A draw AND THOSE TERMINALS DO FAIL with only 20A through them.
There's about 40 of the damn things in the photo below: