Grub Screw – What is it in Vaping?

Definition

A grub screw is a tiny, headless screw that clamps the coilwire inside a rebuildable atomizer (RBA, RDA, RTA or Genesis atomizer). Instead of a traditional slotted head, it has a hex or Torx socket in one end, allowing you to tighten or loosen it with a small allen key. Its sole job is to pinch the coil leg firmly against the deck’s post, creating a secure electrical connection so current can flow from the mod through the coil. Because the screw sits flush or slightly recessed, it keeps the build deck compact and snag-free, making wicking and re-wicking around a Tank“>glass tank or drip well much easier for Australian vapers.

Technical Details

Grub screws are normally M2.5, M3 or M3.5 metric threads, 2–4 mm long, and made from stainless steel, brass or gold-plated copper for lower resistance. The socket is usually 0.9 mm, 1.3 mm or 1.5 mm hex, although Torx T6/T8 versions are appearing on high-end RDAs. The tip can be flat, cup-point or cone-point; cup-point digs slightly into the wire, giving extra grip without shearing. Most atomizers ship with spares in the accessory bag, but thread pitch and length vary between brands—never force a longer screw or you’ll short against the deck. After repeated builds, threads can fill with gunk or e-liquid residue, so a quick rinse in isopropyl alcohol and a gentle toothbrush keeps the socket clean and prevents stripping.

Usage & Tips

• Always insert the coil leg fully into the post hole before tightening; a partial insert can cause arcing and hot spots.
• Tighten gently—”snug plus an eighth-turn” is enough. Over-torquing will snap the screw or chew the hex socket.
• If the screw keeps backing out, remove it, wrap a single strand of 32 ga wire around the threads as a makeshift locker, then re-install.
• Carry a spare allen key in your vapekit; most Aussie vape shops sell individual keys for a few dollars if you lose the original.
• Replace the grub screw at the first sign of rounded socket or corrosion—cheap insurance against a loose coil that could short and vent your battery.

History & Context

Grub screws entered the vape scene with early 2010 Genesis atomizersimported from Eastern Europe. Their low-profile design let capillary wicks sit flat without catching on screw heads. As rebuildables moved from niche forums to mainstream Australian stores, the grub screw became the industry standard, replacing Phillips screws that would strip under torque and contribute to the dreaded gurgling leaks caused by uneven pressure on coil legs.