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What's the gauge thickness of floorpans?

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I am curious, what is the gauge of sheetmetal used in the floorpan of the TR6. I have a micrometer and can measure the thickness of the original floorpan and the Heritage replacement pan I plan on fitting. So what is the formula for gauge = thickness ? Also, I plan on patching over the silly (to me) jacking hole in the floor. Just one less grommet to go bad.
 
The United States Standard Gage for iron and steel sheets and plates was established by Congress in 1893.
It was primarily a weight gage rather than a thickness gage. The equivalent thicknesses were derived from the weight of wrought iron which was taken at 480 pounds per cubic foot making the weight of a 12 inch square by 1 inch thick plate 40 pounds.
So, No. 3 US gage was established to be 10 pounds per square foot = 10/40=0.25.
Thus the thickness changes by the type of material.
14 gage steel = .0747, galvanized sheet = .0785, zinc = .036 all 14 gage.
 
I don't know if the TR6 gauge of the floor pans are the same as my TR3, but according to the gauge charts posted above, both the original and replaced floor pans in my TR3 measure 18 gauge (0.048").
 
Whoa Tom!!

Impressed for sure.

Even in my field (A/E)- few folks are aware that
not all 20 gage sheet metal is the same thickness.

But the TINster knows!! LOL
 
When i re-did the floor of my Spit, I used 18 gauge, worked fine, it welded fine to the surounding floor metal, and is strong.
 
After explaining to my wife, what I was doing, I just finished measuring the old and new floor pans on my six project.

The old pan is what we would refer to as 20 gauge sheet metal, but much to my surprise, the new pan is 21 gauge. Might explaining why some of the new "original" stampings are not as sharp as the real original.

After fighting for years with my wife continually popping the jack hole plug out with her high heels, I too welded mine closed.
 

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That's a jack hole? I would have never guessed that. The only thing I've ever used it for was to drain the interior of water. Many years ago I left the top down overnite and woke up to a deluge that had left a couple inches of water in my beloved TR.
 
I had a 64 TR4, the jack went through that hole and attached to the inner frame. Flats in the rain were fun. Oh, by the way, I too used it as a drain.

And, that 64 TR4 actually came with a hand crank to be used to start the car when Lucas failed (which it did, and crank I did). Were they trying to tell me something?
 
The TR4 Hand cranks are a myth as far as I have ever seen. the earliest car I ever had was a 61 with a 3 diget comm. #
it did not have a crank hole in the radiator to allow for a crank.It may be that some cars were retro-fitted with tr3 bits due to accidents ect. But the 86mm motor is NOT very friendly to this sort of exercise and could well hurt you a lot!!
MD(mad dog)
 
My first TR was a '62 TR4 that I bought with 15k miles on it in early '64. It most definetly had a crank hole in the radiator, and the crank in the trunk. I have no reason to believe it was ever changed. And, yes I did have to use the crank on a couple of occasions. The radiator also had the extention on the upper part of the tank, just like the TR3.
 
Hi Bill I think it is 18 perhaps 20. My 1961 tr3 measures out at 20. Please tell me where are you going to buy your pans?
Sp53
 
[ QUOTE ]
Please tell me where are you going to buy your pans?
Sp53

[/ QUOTE ]

The pans I already have. They are Heritage pans I bought from TRF about a year ago when they were on special.

I am going to mic them to check the thickness, they sure don't feel like 18 gauge steel, maybe 22. We will see.
 
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