Size: You want the plate that supports the router to preferably be large enough to let your router pass through the top hole. This lets you change bits and adjust height without having to climb underneath your router table.

router table insert plateTypically router table inserts are about 9" x 12" and 3/8" thick.

Height Adjustability: Better tables have incorporated leveling pins into the rim of the hole where this insert plate sits. This lets you flush up the router table insert to the surrounding table.

Most insert plates come with two removable rings that accommodate larger vs smaller router bits. Its nice if the design incorporates set screws to flush up the rings with the balance of the insert plate.

If one ring has a standardized 1 3/8" bore to accept your guide bushings (check the size of your bushings, as they are not all the same) it's even better.

Mounting Holes: You're going to need screw holes through the insert plate to attach your router. Some plates come with multiple pre-drilled holes hoping that one set will fit your brand of router. Other inserts come with a paper template with instructions on drilling your own holes.

Its never as easy as they suggest to accurately align and drill the appropriate holes into the plastic, especially if you intend to install your guide bushings into one of the rings in the insert plate.

It is important particularly in this case to get the mounting holes exactly centered with the holes in the plate so your router bits are concentric with the guide bushing or your woodworking accuracy will suffer.

Bottom line ... if you have the option of a pre-drilled template that will fit your brand of wood router, go for it!

Composition: Typically some version of Acrylic, Lexan or Phenolic.... Lexan I believe being the strongest and least likely to warp

Starter Pin: The better router table plates come with a threaded insert to add in a small diameter pin that protrudes out of the insert plate. This is used as a resting place when initiating an edge cut to prevent the router from grabbing and tossing your wood.. you can see it in the top right corner of the router insert plate in the picture above.

In the next article we'll have a quick look at the lower half of the table and your design options.

Portable Router Tables or Tables with a Stand >>