E Thread DIN 40400
Edison Thread

The name Edison thread for the socket of lamps traces back to Thomas Alva Edison.

Thread Size Major Diameter
mm
Tapping
Drill Size
mm
Pitch
mm
E 5.5 5.5 4.9 1.0
E 10 10.0 8.8 1.81
E 14 14.0 12.5 2.82
E 16 16.0 14.7 2.50
E 18 18.0 17.0 3.00
E 27 27.0 24.5 3.62
E 33 33.0 30.8 4.23
E 40 40.0 36.3 6.35