Please Check My Logic and Arithmetic...
Posted: Mon Feb 09, 2015 3:43 pm
According to my 1978 Zeus Precision Data Charts,
a 5/16" UNF bolt has a nominal major diameter of
0.3125" and an effective diameter of 0.2854".
Q: So what is the effective cross sectional area of the bolt?
A: It's Pi-R-Squared...
Q: Please Explain...
A: OK.
Pi is 3.1415926 Approximately
R is the radius, which is half of the diameter.
So we have:
Area = ((0.2854/2) x (0.2854/2)) x 3.1415926
Area = 0.06397 square inches.
Q: So why do you want to know this?
A: Well, someone was taking the piss out of me for saying:
"You could quite easily hang the WHOLE CAR off ONE 5/16" bolt..."
Q: OK, I see your point, you are not in the habit of making unsubstantiated
bullshit statements on this forum, so you want to justify your remarks?
A: Yes -Before I made that remark, I made a few enquiries and
offered the following document as backup evidence...
http://www.americanboltcorp.com/tech/techgr.pdf
Q: So, your point is, exactly?
A: Well, the data in that document says that the weakest 5/16" UNF bolt
they list has a tensile strength minimum poundage of 4,300 pounds.
When I last put my car on the weighbridge, it came to 800Kg, with
me sitting in it.
As there are 2.2046 pounds to the Kilogram, my whole car with me
in it, including "too many pies", would be 1,764 pounds.
Q: So what?
A: Well, if I am not mistaken, 1,764 is less than half the 4,300
pound stated capacity of ONE 5/16" UNF bolt.
Q: OK, you've got me there, but what about the Zeus book data?
(And your stupid calculations...)
A: Well, the bolt document gives the PSI rating for the 5/16" UNF
bolts as 74,000 PSI.
74,000 x 0.06397 square inches = 4,733 pounds capacity for
cross-sectional area the bolt. This compares quite closely with
the 4,300 pound stated in the data.
Q: So you were wrong, then.
A: Yes - Sorry
"You could quite easily hang TWO WHOLE CARS off ONE 5/16" bolt..."
Ian
a 5/16" UNF bolt has a nominal major diameter of
0.3125" and an effective diameter of 0.2854".
Q: So what is the effective cross sectional area of the bolt?
A: It's Pi-R-Squared...
Q: Please Explain...
A: OK.
Pi is 3.1415926 Approximately
R is the radius, which is half of the diameter.
So we have:
Area = ((0.2854/2) x (0.2854/2)) x 3.1415926
Area = 0.06397 square inches.
Q: So why do you want to know this?
A: Well, someone was taking the piss out of me for saying:
"You could quite easily hang the WHOLE CAR off ONE 5/16" bolt..."
Q: OK, I see your point, you are not in the habit of making unsubstantiated
bullshit statements on this forum, so you want to justify your remarks?
A: Yes -Before I made that remark, I made a few enquiries and
offered the following document as backup evidence...
http://www.americanboltcorp.com/tech/techgr.pdf
Q: So, your point is, exactly?
A: Well, the data in that document says that the weakest 5/16" UNF bolt
they list has a tensile strength minimum poundage of 4,300 pounds.
When I last put my car on the weighbridge, it came to 800Kg, with
me sitting in it.
As there are 2.2046 pounds to the Kilogram, my whole car with me
in it, including "too many pies", would be 1,764 pounds.
Q: So what?
A: Well, if I am not mistaken, 1,764 is less than half the 4,300
pound stated capacity of ONE 5/16" UNF bolt.
Q: OK, you've got me there, but what about the Zeus book data?
(And your stupid calculations...)
A: Well, the bolt document gives the PSI rating for the 5/16" UNF
bolts as 74,000 PSI.
74,000 x 0.06397 square inches = 4,733 pounds capacity for
cross-sectional area the bolt. This compares quite closely with
the 4,300 pound stated in the data.
Q: So you were wrong, then.
A: Yes - Sorry
"You could quite easily hang TWO WHOLE CARS off ONE 5/16" bolt..."
Ian
. My 'Flat Earth' comment was meant to emphasise my ignorance not yours.
