….but a stupid fork question.

When you buy forks, do they come with a SFN?

Sometimes…..

I’ve bought 3 sets. 1 did, the others didn’t.

My new ones never have

brand new ones tend not to – the occasional one with a carbon steerer might come with an appropriate bung.

apart from special carbon-safe bits as ww says, I’d assume that a fork as been stripped off a bike if it has a SFN in it

But when I’ve bought headsets they’ve mostly come with SFNs. Except the last Cane Creek one that I bought as separate top & bottom.

And before you ask, they all had crown races too.

Rockshox forks come with a SFN

Rockshox do but never fitted. They don’t cost much if your come without and easy enough to fit. I use a socket (19mm IIRC)to tap it in with.
As Thepurist said headsets sometimes have SFN. Hope come with the heddocter alternative to a SFN which is pretty good but not worth the cost compared to a SFN.

My rockshox and fox forks both came with them,and a few headsets have had them aswell.