Steel Door Institute

The #1 resource for commercial steel doors and frames

The Steel Door Institute (SDI) was established in 1954 as a voluntary, non-profit business association that develops quality and performance standards for steel doors and frames.

SDI’s standards are available without charge. Design professionals around the world specify these standards because they are concise and regularly updated with leading industry practices.

Only SDI Certified manufacturers undergo recurring audits to ensure compliance with our standards for strength, quality and consistency. By specifying SDI Certified, you can be assured you will receive a product that is well-constructed, tested, and evaluated to meet your specifications.

In addition to our trusted industry standards, the SDI website has a Door Selector Tool, Drawings and Videos. We also offer online and in-person continuing education for AIA and GBCI credit.

Steel Doors vs. Wood, Aluminum, and FRP


Steel Doors vs. Wood, Aluminum, and FRP

We gathered data for six months from industry professionals in the US and Canada to get their answers to the question: why steel?

The result is what we believe to be the first ever data-driven comparison on how common door materials perform in fire ratings, blast resistance, acoustics, and more.

View Why Steel >>