Steel Door Inc.

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.

As a complete steel door and frame resource, the SDI website also has a Door Selector Tool Frequently Asked Questions and Product Gallery. We also offer online and in-person continuing education for AIA and GBCI credit.

How to Specify Zinc-Coated Steel Doors and Frames

Remember back when bumpers used to fall off cars? It was because they used to just put chrome plating on the steel instead of a zinc coating, which inhibits corrosion.

Fast forward to 2017 and zinc is the fourth-most consumed metal in the world due to its role in the galvanizing process. These days it’s just about everywhere including your steel door specifications. We still come across specs where the ideal zinc coating isn’t selected, so we’d like to explain the right way to do it.