What works is the 1/4″ spec, which aligns with common electrical standards.
L-Com HGX-NPLATE21 Blank Non-Metallic Mounting Plate for NBE141006/NB121005
You will find that Romex is easy to coil back up without tangling.
110V Electric Hydraulic Hole Puncher MHP20 22 Ton Punching Tool for Steel Copper
1 × Hydraulic Hole Puncher (Exactly as shown in product images). 22 tons punch force, 2–3 seconds per hole punching speed. Equipped with 5 punching die sizes: Φ6.5mm(1/4″), Φ9mm(3/8″), Φ13mm(1/2″), Φ17mm(11/16″), Φ20.5mm(13/16″).
