A connector iron (also called a fusion iron or keratin bonding iron) is a heated tool with flat or shaped pressing tips designed to melt keratin-based glue that comes pre-attached to fusion hair extensions.

The press shape refers to the flat or slightly curved plates that press and mold the melted keratin around the client’s natural hair

What It’s Used For

It is used to:

• Melt keratin bond glue

• Attach individual extension strands to natural hair

• Form a small, secure bond near the scalp

This method is known as keratin fusion installation.

How It Works (Step-by-Step)

1. Section the hair
   A small section of natural hair is isolated.

2. Position the extension
   The keratin-tipped extension is placed near the root (about ½ inch from the scalp).

3. Heat the keratin bond
   The connector iron clamps down on the keratin tip, melting the glue (usually at 180–220°C / 356–428°F).

4. Press and shape
   The press-shaped plates flatten and soften the keratin.

5. Roll or seal
   The stylist rolls or presses the bond with fingers or shaping tools to create a smooth, discreet attachment.

Why the Press Shape Matters

Press-shaped tips:

• Create flat, neat bonds

• Help control glue spread

• Reduce bulky or uneven bonds

• Improve comfort and invisibility

Different tip shapes (flat, U-tip, V-tip, round) are used depending on the extension type and desired bond shape.

Key Benefits

• Strong, long-lasting hold (3–5 months)

• Natural look and movement

• Lightweight and discreet bonds

• Suitable for most hair types

Important Safety Notes

• Must be used by trained professionals

• Excess heat can damage hair

• Always use a heat shield to protect the scalp

• Temperature control is essential

Common Names You May See

• Keratin fusion iron

• Hair extension bonding iron

• Connector iron

• Fusion heat tool