You can look at the drawings but you really don't get the picture untill you put it all together. The 2 center #40 holes inbetween the #12 holes on both ends are machine counter sunk on the leading side. The hinge bracket will fit over them. The platenut on the inboard end gets machine counter sunk as well. Here, all hinge bracket holes are enlarged and all holes under the hinge bracket are machine counter sunk.