Peachtree Woodworking Supply 12 Inch Long Anodized Aluminum Straight Edge Bar with .001 Tolerance | Perfect for Checking Straightness On Metal Surface Tops

Used this to check the flatness of a cylinder head where the exhaust manifold bolts up to. Flat as advertised because I couldn't get my smallest feeler gauge to fit through, but I could get them to fit on the exhaust manifold flange which I knew was warped! I would recommend to anyone who is looking for a cheap and small straight edge.Some people complain about it not being thin and ruler like to see light, but the proper way is to use feeler gauges because light takes a bit more then your smallest feeler gauge to shine through. I personally prefer the thick bottom as it makes it sure to seat flat and not wobble!

It’s straight and accurate. Perfect for what I needed

This straight edge is very well smoothed and finished. There is not a single sharp unfinished edge or corner on the item. This is a pleasant surprise, having gotten used to cheap products on amazon having poor machining, burrs, sharp corners etc. The bottom of this straight edge is 1cm thick, which makes it difficult to look for a crack of light when held against something to check its straightness, but I'm sure there's plenty of other ways to use it.

To measure the flatness of this straight edge, I used a .001 feeler gauge to test at several points along the straight edge. All points measured were less than .001". The feeler gauge itself had been tested using a Mitytoyo 0005" resolution digital caliper. That feeler gauge tested to be exactly .0010" in thicknessThe straight edge is very accurate and well withing the .001" tolerance that is advertised.