dial mounting.

[Kenny C]

Why do some 500 sets have 3 screw mounting? most of mine have two screw mounting. i have 2 with 3 screw mounting and they seem sturdier. Did they stop using 3 screw mounting to save materials?

[LarryInMichigan]

The three-screw mounts were used on the early 500s.  They switched to two-screw mounts sometime in the late 1950s, most likely to save cost.  Someone here will soon supply more details.

Larry

[AE_Collector]

AECo did the same with their 80 desk phones. Then when the 80E came out in 1975 they reduced it again to 1 screw!

I'm sure these changes were all done to save material cost as well as time to manufacture AND maintain them.

Terry