Driving Us Nuts

This week as we had a random call with a customer who wanted some wheel nuts. Nothing odd there you might think, but this is a mine field when look into it, and to cut a potentially long blog post short, we didn’t send any out to the customer as he didn’t know what he wanted. Needless to say the comments were not flattering and we were deemed as awkward. In actual fact it was the exact opposite, let me explain. We could have sent a set of standard nuts out, charged him and thought no more of it, but we will not have it on our conscience that he had fitted the wrong ones fitted to his wheels or studs then had an accident, or damaged his wheels. Yes, you did read that right – accident. Think about this for a moment, in each corner of a car there is a wheel, that wheel is held on by 4 or 5 nuts or bolts, that’s it. If they come off then no wheel and you have an accident, or damage to the wheel which could crack it, fatigue it, uneven wear and tear all sorts of issues. In fact would you believe that most of the restorations we see imported to us, from various places around the world with after market wheels, they have the wrong nuts fitted for that wheel! Yes, everybody knows there are steel wheels, alloy wheels, mag wheels, carbon wheels, one nut does not fit all.

So here is an attempt at trying to explain basics without getting into too much technical detail, this will apply to new cars as well as Classic Mustangs.

There are 3 basic type fastener seats;

  1. Conical Seat – cone shape
  2. Spherical Seat – round or ball shape
  3. Flat Washer – commonly known as Mag Type


Different seats for different nuts or fasteners, the angles of the seat must match the wheel in order to centre it correctly.


There are several different thread sizes used today by vehicle manufacturers;

  1. 12mm X 1.25
  2. 12mm X 1.5
  3. 12mm X 1.75
  4. 14mm X 1.5
  5. 14mm X 2.0
  6. 7/16″ X 20
  7. 1/2″ X 20
  8. 9/16″ X 18

When I mentioned about accidents here is an exaggerated view of what could happen. The wheels could get damaged as a result with movement, under acceleration or braking loads the holes on the wheel may elongate causing some serious issues should we say.


Two other things to remember;

1) do not put oil or lubricant on the threads of either the stud or lugs nuts/bolts

2) re-torque the lug nuts/bolts after 25-50 miles.

Proper Thread Engagement

This is critically important. Make sure you have a minimum thread engagement of the diameter of the vehicle stud (as recommended by SAE – Society of Automotive Engineers). An example is, if the stud size of your vehicle is “½” then you will need a minimum of “½” of threads into the lug nut. If for some reason you do not have this minimum then it is recommended that you use an Extended Thread  Type nut (see illustration above).

Proper Torque (tightening)

This is also very important. Over tightening lug nuts/bolts can fatigue the vehicle studs or lug bolts. Use the SAE recommended torque listed below as a guideline for passenger cars and light trucks;
12mm, 7/16″, 1/2″ = 85 ft/lbs (+/- 5 ft/lbs)
14mm, 9/16″ = 115 ft/lbs (+/- 5 ft/lbs)

Mustang Specific Now:

We have a little table below that should help with the basics as fitted from stock.


At Mustang Maniac we stock a large range of wheels, stock, after market and specialist even racing, we stock an even larger range of wheel nuts, hopefully we will have everything you need for your wheels. The various guides above only scratch the surface, an example is that some washer based nuts also have the correct way round to fit them too, then there are the offset washers to enable various fittings that could be a generic fit wheel or custom wheels or where space is tight to the centre hub. Here we have a selection of our range of our chrome nuts where we try to show the differences side by side.


There are open-ended nuts, closed nuts, short nuts, long nuts, chrome nuts, steel nuts, alloy nuts, black nuts, left hand thread nuts, right hand thread nuts, long shank, short shank etc. ALL of which make a crucial difference to your wheels.




So as you can see when we ask what sort of wheel nuts you want – it’s a sensible question not us being awkward at all, we are looking out for you. Simple reason is that we do have a conscience and won’t just sell you anything, but we can’t validate what you order from our WebShop of course. So please make sure you have the correct fasteners for your wheels.

We will plan to copy this post as an article shortly too ready for easy access. Was this any use to you out there, please let us know.

Customer Cars:

Acapulco Coupe has taken some leaps forward again this week. Yogi has finished fitting up the custom exhaust and made a good job of the step down from the headers to the pipes. The only thing to be careful of here is the lowest point of the car is the flange fittings for the exhaust now.

The rest of the exhaust has now been aligned up correctly and fastened up. We are going to wait and see how she sounds and performs if we need to add a cross flow pipe.


We have also used something called copper-nickel for the transmission lines and fuel lines. Although they look copper now they will tone down and look more like steel as they age nicely. We use our own custom-made and design brass fittings to the bottom of the radiator.

She even has a new set of boots we have just fitted and balanced.


We even got to the point where we have filled her up with fluids to check for any static leaks before we fire her up.

About Mustang Maniac

A business dedicated to restoration of Classic Mustangs. We supply parts for all ages of Mustangs 1964 to present day, servicing, restoration and custom builds. Anything your Mustang needs, we can help.
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