The #1 Resource for

Steel Doors & Frames

The Steel Door Institute produces quality and performance standards for steel doors and frames. And as the door and hardware industry evolves, our standards are updated to reflect current best practices. By specifying steel doors and frames to our standards and from SDI Certified manufacturers, you can be assured to receive high-quality products that fit your specific needs.

Choose Quality

Specify SDI Certified

Anyone specifying or purchasing a steel door or frame from an SDI member company can be confident that the product has been tested and approved by the most respected laboratories in the country, and that it’s backed up by a commitment to service and support you can count on. All SDI certified members proudly manufacture their doors and frames in the USA.

How to Install Steel Doors and Frames

People often blame the manufacturer when there are issues with their standard or custom steel doors and frames, when in fact the problem lies with poor installation. With these step-by-step guides, there is NO EXCUSE for improper installation!

Knockdown vs
Welded Frames

The two common types of frames and elevations are knock down (KD) and welded. See the most popular types of KD and welded frame constructions, along with the pros and cons of each.


Help yourself to models and details in PDF, AutoCAD, Revit, and SketchUp formats.

Stay Informed

Join over 7,000 architects who receive quarterly tips on steel doors and frames. 

Door Selector

This tool helps you choose the appropriate doors for your projects. Start by clicking the building type and opening to see the most common door specifications based on your criteria.