It is a length of 0.001 inches.
http://wiki.answers.com/Q/What_is_a_thousandth_of_...

1. Convert the 1/1000 inch to .001 inch. One inch is equal to 25.4 millimeters, or mm. Multiply .001 by 25.4 mm. So for every .001 inch, there is .0254 mm. 2. Input your own numbers
http://www.ehow.com/how_7913465_convertthousandth...

That would take me to long to find out. Unfortunately ChaCha only gives me 10
http://www.chacha.com/question/howmanythousandth...

25.4mm in an inch. 0.0254mm in one thousandth of an inch so 1.3/0.0254 = 51.1811 thousandths of an inch.
http://answers.yahoo.com/question/index?qid=201001...
