If any step fails, use a nappy fastener (6,3)

I believe the answer is:

safety pin

I'm a little stuck... Click here to teach me more about this clue!

'fastener' is the definition.
(safety pin is a kind of fastener)

'if any step fails' is the wordplay.
'fails' indicates anagramming the letters (a failed spelling).
'if'+'any'+'step'='ifanystep'
'ifanystep' anagrammed gives 'SAFETY-PIN'.

'use a nappy' is the link.
This may not be correct. Some or all of it may be part of another bit of the clue.

Can you help me to learn more?

(Other definitions for safety pin that I've seen before include "Metal fastener" , "Fastener with covered end" , "Grenade release mechanism" , "Simple fastener" , "explosive feature?" .)

I've seen this clue in the Sydney Morning Herald.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.