Recently, I've had to identify a residential spring hinge for replacement. The owner doesn't like the finish and now this 15 year old hinge was starting to pit and tarnish.  I thought I'd share with you my easy button.

1st of all here is what needed to be identified - It is a Bommer Spring Hinge 4" x 4" with 5/8" radius corners. It a little deceptive that looks "standard". But these screw holes are not the standard residential hinge screw hole pattern.

Bommer Spring Hinge 4 x 4 with 5/8" radius corner               

This was my first picture, without any adjustments.

For my second picture - I took a straight on shot and then rotated it 90 degrees in my computer software.Bommer Spring Hinge 4 x 4 with 5/8" radius corner

Finding and comparing the centerline of screw holes is the key to identify the hinge.

The biggest problem is locating the centerlines in this pictures. So I opened my picture in Paint program.....

And here is my Easy Button....

easy button magnifying glass to line up the centerlines

Once I pressed the magnifying button a rectangle appeared on my screen, and as long as I didn't click anything, I could line up the center of the centers of the screws with the tape measurer in the shot.

After knowing this is a Bommer Spring Hinge, I found out they have 4 different possibilities for the hinge replacement depending on the manufacturer of the door and each have different centerlines of the screw holes.

This hinge is a proprietary hinge. It is used on Pease Doors.

Boiling all the supper sleuthing down... This is a Bommer LB4340 4 x 4 hinge