While there isn't a single definitive instrumental track titled that dominates the charts, the name is frequently used by bands like Rusty Nail (an Irish rock band from St. Louis) or associated with instrumental versions of songs like Moderat's "Rusty Nails" .
Use "biting" guitar tones or distorted synth leads to mimic the "metal" aspect.
Incorporate mechanical or industrial sounds like clinking glass or metallic scraping to build a unique world for the listener. Rusty Nail - Instrumental
Create singable melodies on the guitar or synth. Even without lyrics, a strong motif gives the listener something to hold onto.
To live up to the name "Rusty Nail," the music should reflect the qualities of the object: metallic, aged, sharp, and perhaps a bit dangerous. While there isn't a single definitive instrumental track
Writing an instrumental requires the lead instrument to act as the "voice" of the song.
If you're trying to strip vocals from an existing song to create an instrumental version: To live up to the name "Rusty Nail,"
If you're building from scratch, Cubase or similar software allows you to layer "Lego blocks" of sound to find the right direction.