Replacing Wood or Hollow Metal Doors in Existing Hollow Metal Frames
Each manufacturer has their own hinge and lock locations. Some companies hinge locations are the same, but most companies have “something” a little bit different.
For example, Amweld doors have the same hinge & lock locations as Steelcraft. Their doors and frames have the hinge backset smaller though. If you use a Steelcraft door in an Amweld frame, then there will be hinge binding (it doesn’t close right). BUT you can use an Amweld door in a Steelcraft opening without any problems.
Amweld, Steelcraft & Republic all have the same hinge/lock locations for the 6/8 door opening. The hinge backset is the only difference on the Amweld frame. Also, be aware that these doors can be flipped upside down when there is a 3/4" undercut. Amweld & Steelcraft 7/0 doors without locks can also be flipped upside down (again 3/4" undercut).
There are also many companies that use 5” as their top hinge dimension (Top of frame to top of hinge). This stems from the term “5-10 and Equal”. This means 5” down to the top hinge, 10” up from the bottom, and Equal in the center (all these dimensions are taken from the frame). Most of these companies have the lock in a different location.
The best tip I can give you if you are replacing a door in an existing frame is to measure the width of the frame in 3 or 4 places to know the true width of the opening. Some of the time, the frames will bow inward at the center, close to the strike location (or middle hinge). Sometimes the frame is undersized at the bottom of the opening. If it is a Double door, the frame may sag in the center. This condition is harder to check for.
Quite a few companies manufacture their Hollow Metal Doors with inverted top and bottom channels. This is so they may be cut or grinded down in the shop or field for abnormal floor conditions or bowed heads. Make sure you request a top cap if you have an inverted top channel on an exterior door. Many times a door will rust from within due to water, snow or ice sitting in a inverted top channel.
In closing I’d like to also caution – beware of the 7/10’s. Sometimes companies use 8/0 frames and cut 2” off the bottom of the hinge jamb & 2” off the top of the strike jamb. Pay extra attention to the hinge and lock locations, do not assume. Also, neither chart gives information about Dutch Door Openings.