Review on 5 Pack of 15x20cm Double-Sided PCB Boards - Universal Printed Circuit Prototyping Boards for DIY Soldering Electronic Projects and Practice Test Circuits by Mike Barnett

I have yet to solder these boards but they look very nice and I don't expect any soldering problems as the boards are well tinned and have very well defined and clean pads. What I really like about them is the mechanical precision. The holes are precisely 0.040 inch in diameter and 0.100 on centers in the x and y directions. The most amazing thing is that the holes match the solder pads very well. I have purchased several mechanical screw connectors that are .200" (5.08mm) center. which can be folded/threaded next to each other. Which doesn't come across very often, but is very valuable when you need to stack them. However, these connectors have .040 square pins that will not fit in a standard round hole with a diameter equal to the width of these square pins. The diagonals are, of course, twice the square root, or 0.0566 inches. So the holes should be about this size. (Willwin 10 Set 9-Pin 5.08mm Pitch Male Female Screw Terminal Block PCB) I was able to put this board on my router and re-drill a series of 74 holes automatically with a .056, #54 bit every .1000". After that , all the holes were still right in the middle of the pads and the plugs were properly seated and the solder still had room for the pad!I've done this 4 times on one board and each row was great.Then I cut the board two and in of the right size.Of course this can be done by hand but it will take some time to make the required number of holes.Maybe I'll buy a few more of these boards and maybe both sizes.