On Thu, 20 Sep 2007 23:08:32 GMT The Medway Handyman wrote :
Ok great, so what do Z, B, D & I stand for?

Sorry, drifting into shorthand

B = breadth (width) D = Depth

Z = elastic modulus (put simply, relative strength)

I = moment of inertia (relative stiffness)

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk