BF Pin (Bottom Feeder Pin) – What is it in Vaping?

Definition

A BF Pin (Bottom Feeder Pin) is a hollow, spring-loaded 510-pin installed in bottom-feeder atomisers and box mods. When a squonk bottle inside the mod is squeezed, e-liquid travels up through the pin and directly onto the Deck“>build deck or bottom-coil wicks, eliminating the need to drip manually. The BF pin is the heart of Australia’s popular squonk setups, letting vapers enjoy dripper flavour without carrying juice bottles.

Technical Details

Standard BF pins are 4.5–5 mm long with a 0.8–1 mm central bore, machined from gold-plated brass or stainless steel for low voltage drop. Inside the 510 connector, the pin’s hollow channel mates with a silicone squonk bottle tube; a Delrin seal prevents flooding the battery compartment. Two common variations exist: fixed hollow pins (tightest seal, best for single-coil RDAs) and spring-loaded BF pins (self-adjusting, ideal for hybrid 510 caps on mechanical box mods). Always verify Thread“>510 thread length (±0.5 mm) to avoid battery shorts.

Usage & Tips

• Before first use, prime the wick, then gently squeeze the squonk bottle until a tiny drop appears at the coil—over-squonking causes spit-back.
• If leaking occurs, check the O-ring under the BF pin; replace if nicked.
• Clean the hollow channel weekly with a 1 mm Allen key wrapped in paper towel to remove sweetener build-up.
• Never use a BF pin on a non-squonk mod; the open centre will dump juice onto your battery tray.

History & Context

The BF pin debuted in 2009 on Filipino “JuiceBox” mods, but only gained global traction after affordable 3 mm CNC pins reached the Australian market around 2015. Today, virtually every rebuildable atomiser ships with both solid and BF pins, reflecting squonking’s rise as the nation’s favourite drip alternative.