I am trying to make a Eagle library for a Micro USB B connector. The library is unavailable and I decided to make one with the datasheet dimensions provided. But it is rather confusing.

The units are in mm Please check the attached image.

The Dimensions are shown as subtracted from another. Like A-B I thought that was a tolerance.

I have marked the rear pin. As the top view the size of the pin is 4-1.00 But as Y the size is 2-2.00!! So the error is like 4mm??

Please advice me how to read this dimensions in the datasheet. I do not get that 2-2.00 notation. enter image description here


1 Answer 1


The 2-2.00 dimension (your Y) is 2.00mm, but it applies to two identical holes (2-) on the datasheet. Only one of those holes is dimensioned for length, the other is dimensioned for width, to avoid an excess of lines and dimensions cluttering the drawing. You are expected to figure out which pair of holes are the same size from the symmetry of the drawing.

Similarly, the socket has 4 tabs 1mm wide, X, shown as 4-1.00

  • \$\begingroup\$ Thank you very much for taking your time to help me out. I did a little research and as I understood 4-1.00 First view (marked as X) suggests that the dimension can be 4mm or 3mm. 2-2.00 Second view(marked as Y) suggests the dimension is 2mm But it is for the same side of the same pin!!! Shouldn't the dimensions be the same? Literally the pin is same. That is the width of the pin. \$\endgroup\$ Commented Dec 29, 2019 at 10:47
  • 6
    \$\begingroup\$ No, the upper drawing shows the component dimensions, 4 x 1.00 mm, for the four pins. The lower drawing shows the PCB dimensions and all the holes are oversized at 1.6 to 2.0 mm. It looks to me that the plastic pegs are the insertion references and that the pins may vary with respect to the pegs. \$\endgroup\$
    – Transistor
    Commented Dec 29, 2019 at 10:58

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