metal 90 degree corner bead

A metal 90-degree corner bead is one of the most common drywall finishing products. Here’s a focused explanation:

What is a Metal 90-Degree Corner Bead?

• Purpose: It reinforces and protects external drywall corners, giving them a sharp, clean, and durable 90° (right angle) edge.

• Material: Usually made from galvanized steel (to prevent rust) or sometimes aluminum.

• Shape: Forms a perfect 90° angle down the corner, with flanges (wings) on each side to embed into the drywall mud.

• Installation Methods:

  • Nailed

  • Screwed

  • Stapled

  • Crimped (using a crimping tool)

  • Or set into joint compound ("mud") alone.

Types of Metal 90-Degree Corner Beads

Typical Sizes

• Length: 8 ft (2.4m), 10 ft (3m), 12 ft (3.6m)

• Flange Widths: Commonly 1 1/4" to 1 1/2" (about 30–38mm) on each side.

Advantages

• Sharp, professional 90° angle.

• Protects against dents, chips, and wear.

• Makes corners straighter and easier to finish.

• Galvanized types resist corrosion.

Quick Installation Steps

1. Cut the bead to length with tin snips.

2. Fasten it along the drywall corner with nails, screws, or crimpers.

3. Apply joint compound over the bead.

4. Smooth it out with a drywall knife.

5. Sand after drying for a flawless finish.