MTFCA Forum

Howdy folks.

I often run Motocraft F 11 plugs and would like to use a knurled nut. does anyone know the thread size and pitch at the top of the plug? A web search failed to find such details.

Maybe someone knows where I can buy such a thing? Perhaps I'll need to buy something smaller and tap it.

I know it's just cosmetics but I would like to do this

Thanks

Ben

I didn’t check, but Restoration Supply carries a bunch of hard to find parts for antique cars

Heck go to Lowe’s or Home Depot and in the specialty section they carry the knurled nuts in multiple sizes. Take your spark plug in and find the right size with their displays. I found the size I needed from an appearance standpoint then tapped to the size of the stud. 14 cost about $10 but I could have ordered a bag for less. Best John

Also try Ace Hardware. They have a good selection of nuts of all types including the knurled nuts. If there is a large farm and ranch store such as Atwood’s or Tractor supply in your area they also have small hardware selections.

I'm pretty sure those are metric !

RajoRacer wrote: ↑

Sun May 12, 2024 3:52 pm

I'm pretty sure those are metric !

You are correct. Metric threaded plugs have metric nuts
By Seth Harbuck, Shreveport, LA. on Tuesday, September 22, 2009
Oh, by the way, if some of you are interested in replacing the screw-on terminals with knurled brass thumbnut for "the look" , the threads on the studs are not #6-32, they are M4 x 0.7 (or at least they were on mine)

As I recall......... I used a 4mm tap & ran it thru the 6-32 nuts. Same problem solved.

That’s why I mentioned to tap the nut to the size needed

I should follow up, Motocraft F 11 nut is M4 .7 (metric) a nice choice is amazon, $7 for 6 pieces
uxcell Knurled Thumb Nuts, 6Pcs M4 x D12mm x H8mm Brass High Head Through Hole with Collar High Head Through Hole Round Knobs Fasteners for 3D Printer Parts, Machine Tools

[Thread Size] M4: Pitch: 0.7mm/0.03 "; Large end diameter: 12mm/0.47 "; Small end diameter: 8mm/0.31 "; Total thickness: 8mm/0.31 ".

FYI

Ben

The Autolite 3095 already has the threaded top and is available at the local Autozone for cheap