Why Thru-Bolts Are Not Recommended for Hollow Metal Doors (And Why Sex Bolts Are Better)

When installing hardware on hollow metal doors, choosing the right fasteners is essential. Many people assume thru-bolts are a reliable option, but in reality, they can cause structural damage and security issues. Instead, sex bolts for hollow metal doors offer a more secure and durable solution.

In this post, we’ll explore why thru-bolts should not be used on hollow metal doors and why sex bolts are the best alternative.

Why Thru-Bolts Are Bad for Hollow Metal Doors

Thru-bolts are a common fastener type that passes entirely through the door, requiring a nut on the opposite side. While they may work well on solid wood or composite doors, they pose several risks for hollow metal doors:

1. Thru-Bolts Weaken Hollow Metal Doors

Hollow metal doors are made from thin steel skins wrapped around a core. Drilling through both skins for a thru-bolt can reduce the door’s structural integrity. Over time, repeated stress can cause the metal to deform or weaken.

2. Poor Support Inside Hollow Metal Doors

Unlike solid-core doors, hollow metal doors lack sufficient internal support for a traditional nut and bolt setup. This can lead to hardware loosening or failing due to lack of grip inside the door.

3. Security and Aesthetic Issues

• Thru-bolts leave exposed hardware on the door exterior, making them an easy target for tampering.
• They can also create an unsightly appearance, especially in high-traffic commercial spaces.

Why Sex Bolts Are Better for Hollow Metal Doors

Unlike thru-bolts, sex bolts are specifically designed for hollow metal doors. Also called barrel bolts or Chicago screws, they feature a male and female component that securely fastens together.

1. Sex Bolts Maintain Structural Integrity

Sex bolts distribute force evenly across the door’s surface, reducing stress on the metal skins. This helps preserve the door’s strength and longevity.

2. Secure and Long-Lasting Fastening

Because sex bolts thread into themselves, they won’t loosen as easily as a standard thru-bolt and nut. This makes them ideal for high-use applications like panic bars and door closers.

3. Improved Aesthetics and Security

• Flush-mounted sex bolts provide a clean, professional look on both sides of the door.
• Their design reduces the risk of tampering, making them the preferred choice for commercial and industrial buildings.

Conclusion: Use Sex Bolts, Not Thru-Bolts, for Hollow Metal Doors

When installing hardware on hollow metal doors, choosing the right fasteners is critical. Thru-bolts can weaken the door, loosen over time, and pose security risks. In contrast, sex bolts for hollow metal doors provide a stronger, more secure, and aesthetically pleasing fastening solution.

For commercial door installations, always opt for sex bolts—they’ll ensure your hardware stays in place and your doors remain strong for years to come.

Need Help Choosing the Right Fasteners?

If you’re unsure which type of fastener is best for your specific door and hardware setup, consult with a Dutch Door Hardware specialist. Proper installation is key to maximizing security and performance!