more help please

[dottad]

Hi again,

Sorry to be a bother, but bought a keencut edge last week and when I had a look at it it was bent at both ends and so wouldn't lay flat on bench. I phoned up supplier and left message for someone to phone me to discuss.
They did better than that and sent carrier in to collect it for return. When they got it back and had a look at it, they laid it out and with weights got it to lay flat. They phoned me up and asked if seeing as it was now flat would I take it back. I said yes and they know better than me. It arrived today, and although not completely flat it is nearly so, but when you draw a line with it and compare it with a straight edge from our engineering department (just newly been callibrated) it runs off a tiny fraction before coming back into line again. When I say a tiny bit I mean a fraction of a mm.

My question is, would this be absolutely critical in cutting mountboard square or would the smallness that this is out be okay. If it isn't going to make a difference, then I'm happy to keep it, but if its a problem then I would obviously need to send it back.
I can't afford fancy board cutters and I bought this soley to cut the large sheets of mountboard to size before cutting my aparture as I only have a manual mountcutter and nothing too fancy (yet - maybe oneday!!)

[Roboframer]

Not sure what a Keencut edge is - a large steel ruler/straight edge?

I've got one - Maped - in fact I've got two - one is just for washlines.

I think a basic requirement is that it should be, er, straight! Send it back and demand a replacement.

[Not your average framer]

I've got a Maun 36" steel rule, it's about 6mm thick, it's made of hard ground flat steel, usefully heavy and virtually indestructable. You can't damage the edge with a blade, the steel is just too hard for that! I got mine years ago from Russell Bookcrafts, but you can get them from most tool catalogue companies including Axminster Power Tools who I think do one even longer than mine.
Cheers,
Mark