A Slab ‘o Granite

Precision requires precision tools, there is no two ways about it.

Whether it is assuring that your square is square, your plane blades are honed to just the right angle, straight edges are straight etc, it is beneficial to have a true surface to reference off.  Taking that one step further, where it comes to sharpening particularly, if you are relying on a flat surface to create a reference plane (either the surface you use to dress your waterstones for example, or a surface to conduct the Scary-Sharp technique), then you need a surface who’s flatness is assured.

And what better way than a solid slab of granite?  You can get it wet without fear of rusting, it is dimensionally stable through a wide temperature range, and is comparatively inexpensive.

I picked up this tool from Carbatec – a Granite Surface Plate.

Granite Surface Plate

Measuring 300x230x50mm (12″x9″x2″) and weighing in at around 12kg, the real significance comes in when you look how flat it is.

It comes with a certificate of testing, and in this case, the block has a variance of 0.00008″ (2.1 microns, or 0.0021mm) over 7.5″.  So she’s pretty flat.

Certificate of Testing

It will be featuring in some sharpening episodes in the near future