I got these used wheels for my F-350. I noticed the lug holes have cone-shaped recesses, so I assumed I needed cone nuts, and I bought some, which are unfortunately the wrong thread pitch. However, I just now noticed that the stock flat flange lug nut will fit perfectly into the flat portion of the hole (see pic). So, is this wheel designed to accept either cone or flat lug nuts and can I safely use the stock nuts?

 

tapered lug nuts are used on lug centric wheels
(where the center hole does not fit tight to the center hub of the axle.)
flat lug nuts are used on hub centric wheels
(where the center hole of the wheel fits tight to the axle hub.)
in other words, you can not use flat lug nuts on lug centric wheels.

what year truck and wheels?? if it is 99 and newer, than it is hub centric and the flat lug nuts are the proper ones.
if it is 97 or older, it needs tapered lug nuts and the flat ones will not work, because 97 and older was lug centric, 99 and newer are hub centric.

 

The truck is 2000. The wheels are aftermarket, and the guy I got them from said they are American Eagle and came off a 2002 F-350. If the stock wheels are hub centric, would aftermarket wheels be also?

 

Hard to tell from the pickup but are those tapered holes? Aftermarket wheels are often not hub Centric.

 

The holes have a taper in them, but they also have a flat part that the flat lug nut sits on just exactly.

 

I would only use tapered lug nuts on that wheel.

 

X2 on that comment, it's also my understanding that the company is out of business now too, so no Tech Support for information on the Correct Lug Nutz

as what was mentioned before about Hub Centric or Lug Centric is true https://www.gregsmithequipment.com/H...Vs-Lug-Centric

You can get Hub Centric Rings too. https://www.discounttire.com/learn/h...vs-lug-centric

I just went thru this BS with Wheels for my boat trailer and no one could Balance the Damned things because they all tried to Balance via the Hub, I finally Found one of the older tire stores that had older equipment and they were able to balance them with no issue.

 

BTW - I saw that Gorilla Automotive does carry Alcoa style lug nuts - they are good quality and IIRC they warranty against rust, etc.

 

Those wheels are for acorn/tapered lug nuts. The flat lug-nut may “fit” but it isn’t the correct application.