Fan measurement

[Tazdrummer]

How do you measure a fan? I am trying to find a grill for these monsterous fans I have.

It is approximately 5 inches from left to right corner (upper corner to upper corner) and 5 inches from top to bottom. Approximately 1.5 inches thick. The writing on the back of the fan says "12V-(6-14V-) 6,5W 3350U/min" So I know it will run on 12 Volts and pull about 5 to 6 Watts but what is the 3350 U/min?

Thanks

[ephmynus]

What's up Taz the 3350 number pertains to the revolutions per minute. This means that your fan goes around at 3350RPM. Just off the top of my head, 5 inches sounds about like a 120mm fan and that is the size fan grill you will need.

[Darren Wilson]

120mm is nearer 4" than 5", but I would say that a 120mm fan grill is the size that you would need.

[ephmynus]

[quote]Originally posted by Darren Wilson:
<strong>120mm is nearer 4" than 5", but I would say that a 120mm fan grill is the size that you would need.</strong><hr></blockquote>


Yea, I was rounding but I figured Taz was too. I think 120mm is about 4 3/4"

[DonJ]

120mm translates to 4.724409448 inches. (One inch equals 25.4mm, exactly.)
I have a standard box fan here and it is 120mm from outer edge to outer edge...and 105 mm (4.133858267 inches) from center hole to center hole.

[Falanx]

</font><blockquote><font size="1" face="Trebuchet MS, Verdana, Arial, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Trebuchet MS, Verdana, Arial, Helvetica, sans-serif">Originally posted by DonJ:
<strong>120mm translates to 4.724409448 inches. (One inch equals 25.4mm, exactly.)
I have a standard box fan here and it is 120mm from outer edge to outer edge...and 105 mm (4.133858267 inches) from center hole to center hole.</strong></font><hr /></blockquote><font size="2" face="Trebuchet MS, Verdana, Arial, Helvetica, sans-serif">If we're going to be exact, then you must remember that the two scales, metric an imeprial are not meant to be convertable. To only four decimal places, one inch = 25.3991mm. The actual figure approximates irrational, until you get to the atomic level.

[Falanx]

</font><blockquote><font size="1" face="Trebuchet MS, Verdana, Arial, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Trebuchet MS, Verdana, Arial, Helvetica, sans-serif">Originally posted by DonJ:
<strong>120mm translates to 4.724409448 inches. (One inch equals 25.4mm, exactly.)
I have a standard box fan here and it is 120mm from outer edge to outer edge...and 105 mm (4.133858267 inches) from center hole to center hole.</strong></font><hr /></blockquote><font size="2" face="Trebuchet MS, Verdana, Arial, Helvetica, sans-serif">If we're going to be exact, then you must remember that the two scales, metric an imeprial are not meant to be convertable. To only four decimal places, one inch = 25.3991mm. The actual figure approximates irrational, until you get to the atomic level.

[DonJ]

One inch equals 25.4 mm...EXACTLY!!! And yes, it is meant to convert directly from one to the other. You can carry it out to 12 decimal places if you want and it will still be 25.400000000000 mm.
But hey, don't take my word for it. I've only taken college level courses of chemistry, physics, calculus, differential equations, etc. and I passed all of them. But again, don't listen to me...look it up yourself in any reference book.

[Platypus]

It depends on whether you convert to International or Survey measurement. The International Foot and the Survey Foot are converted to Metric by different means, one fractional, one decimal, so a slightly different result is obtained.

An International Foot is 0.999998 (Exactly) of a Survey Foot.

1 Survey Foot=1200/3937 Meter (Exactly)
1 International Foot=12 x 0.0254 Meter (Exactly)

The International Foot is conventionally used for conversion - 1 Inch = 25.4mm exactly.

Source: National Institute of Standards & Technology, Office of Weights & Measures

<a href="http://ts.nist.gov/ts/htdocs/230/235/appxc/appxc.htm" target="_blank">http://ts.nist.gov/ts/htdocs/230/235/appxc/appxc.htm</a>

[Outcoded]

All that **** aside (I used to be an engineer, don't get me started), answering the question. Measure from the centres of diagonally opposite mounting holes. Grills are normally sold in metric sizes.

[condor]

Kids..

does it really matter if 1" is 25.4 or 25.3991 or whatever? NOT !!!!!!!

What does that have to do with the question ?

Grills come in mm sizes usually it's either 50mm, 60mm, 80mm, 92mm or 120mm

if it's a standard fan it should fall in one of those categories..