Headlight Nut Size


Mine is only two inches though.
10 Year Member
Oct 11, 2011
Waldorf, MD
I ordered my headlights and completely forgot to order the nuts to go with it anybody have any clue what size they are I just tried a 1/4 20 nut and it threaded just a half a thread so its gotta be metric im thinking 8mm or something if anybody could help me that would be excellent that way I can go to home depot and get them.
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1 MM=.0393", so
6 MM=.235 (a little smaller than 1/4" .250)
7 MM=.275" (a little larger than 1/4" .250)
8MM = .314" ( a little smaller than 5/16" .316)

The hex heads on the adjuster screws are 5/32" and will probably require you to buy another 1/4" drive shallow socket.

Bonus item:
Aftermarket headlight lens kit - It took about 7 days to get the lenses, 20 minutes per side to install all 3 lenses and forever to try to align them.

If you bought Genuine Ford headlights, the adjustment will be easy. If you bought reproduction headlights, they will be very difficult to align properly. I bought reproduction units the first time, and my headlights could not be aligned: they would shine up in the trees and across the road. I even had all 3 screws set up as adjustment screws.

I drove around for several days with the driver’s side headlight scanning the upper branches of trees for squirrels, owls and UFO’s. The headlight lens had extra slack between the retaining clip and the screw head which allowed the lens to shift around. I fixed that with some small washers between the screw heads and the bottom of the mounting hole. I would recommend that you find 2 extra adjustment screws per side - they are the ones with the hex ends on the end of the screw where it sticks through the mounting plate. That may help the alignment problems, as the stock setup only allows adjustment with 2 screws, and is hard to adjust in and down at the same time.

The adjustment screws are upper inside and lower outside screws. If the headlights were re-assembled properly, they will have a 5/32" hex on the screw. You can use a 1/4" ratchet with a 5/32" socket. The upper screws can be reached with the hood up, while the lower screws may require you to lay on the ground in front of the car and reach them from the bottom.

To align the headlights, find a level spot with a wall 25-30 feet away. Disconnect the driver light and align up the passenger light so that the light pattern is slightly below of the actual centerline of the headlight. This is to illuminate the right hand side of the road. Reconnect the driver light and disconnect the passenger light. The driver light should be aimed so that the light pattern on the wall is inward about 6" and slightly below the centerline of the headlight. This keeps you from blinding the oncoming cars. Disconnecting and reconnecting the headlights helps to show which headlight is shining in what direction. Reproduction headlights may shine in several directions at the same time, making it very difficult to align them if both lights are on at the same time

One Stangnetter recommends putting a fender cover over the headlight that isn't being aligned. I like his idea, it's simpler than disconnecting the lamps.