I have a F350 Dually.

Some of the lugnuts had a flat base, like a flange.

The other lugnuts on the truck were acorn style, with \__/ base.

I put on new ones with the \__/ all the way around (chrome) after I painted the steel wheels.

I have them torqued down with a torque wrench.

I see most duallys running flanged lug nuts. Or some had lugs with washers.

Am I creating a safety hazard with the lugs I used? I didn't think it was a big deal, but wanted to ask before I started driving it alot, as it sees some towing use.

Thanks.

 

what ive seen is when flange type nuts are used, theres a machined surface that contacts the i.d. of the wheel to center and carry the load, the only job of the lugnut is to hold it up on the machined surface.hope that helps.

 

Thanks for the reply, I've been driving it some, figuring that the style on there was the same as what I took off for the most part.

Since making this post I've seen several different styles on trucks as I look around.

Still not sure if it's the right way to do things. Although they seem like they are doing the job.

 

It truly depends on what type of wheel you have on your truck. If you have a flat surface around the lug hole on your wheel, use the flat lug nuts. If you have a conical surface around the lug hole, use the acorn type lug nuts.

The job of the lug nuts is to clamp the wheel to the truck. The acorn style of lug nut also has the added function of centering the wheel on the hub. The flange style uses some different method of centering the wheel, which varies by application.

Using the wrong type of lug nut on your wheel is OK for an emergency, but bad over the long term. The amount of surface contact (wheel to lug nut) is what provides clamping force and keeps the lug nuts from backing off the lug studs. Clamping force is reduced if there is an incorrect type match. Not to mention, distortion and warping of the wheel can be caused by type mismatch. Believe me, you NEVER want race your own tire down the road, the tire will win. I know.

When changing from one type of wheel mount to the other, you need the correct lug nut type to match if you want to be safe.

I can get you pics of flange wheels and lugs if you want. I have a set in my garage. I went to acorn type wheels and lug nuts (black ones shown on my truck).

 

The lug nuts with the flanges are for hub centric wheels. These wheels fit centered on the hub. The acorn style lug nuts center the wheel on the studs.
Dont mix and match.