Maun 1700-001 Steel Straight Edge Metric 1000 mm | Mark and Cut Accurate Straight Lines | Accurate To 0.084 mm Per Metre | For Hobby, Craftwork and Decorating |Professional Quality

I bought the 12" straight edge for checking the flatness of hand planes (No. 4 and block planes). It it perfectly straight. You can check by using a sharp knife to scribe a thin line, flipping over, lining up the ends points and repeating. It is a quality tool. It is thin so it doesn't stand up on its own, but I use it by hand and its thinness makes it lighter and thus easier to hold, especially across the narrow width of a hand plane. If it was too heavy, it would be harder to hold steady whilst holding something like a hand plane up to a bright light to check for gaps. It is stamped as machined to within 0.01% of its length. Do the maths! That's 1.2 thou over it's 12 inch length. Plenty straight!!! 12" is such an easy size to handle by hand. It has a hole in one end so it hangs nicely from an angled wooden dowel. Great product made in the Midlands UK. And they say we can't make anything anymore?

Price is fair but only one side is straight edge and even then, on this one, is some minor defects in steel that I feel may affect precision. Simply by sliding finger or nail over edge, you feel some uneven areas. Ordered to measure cylinder head flatness, however did not use as would not trust. Probable perfect for wood work but not engine work if you care for perfectly flat surface! Returning for refund :-(