Shinwa Sokutei 12130 Curved Scale, Small, Stainless Steel with Grooves, Front and Back Side, 11.8 x 5.9 inches (30 x 15 cm)

I tested it when it arrived in the usual manner for testing squares. It is perfectly square. I like that it is small as it fits into the type of woodworking that I do. It's fairly rigid and well made. Glad I got it.

I was worried these would be thin and floppy, but that is definitely not the case. These are 1mm thick stainless and perfect for using as a parallel cutting guide. I have fairly large hands, but the small size of this L-square makes it easy to hold in place with just my thumb and pushed against the edge guide of my worktop. It is nicely square on the outside edges (as checked with a perpendicular line drawn from a straight-edge) and ever so slightly off on the inside edge. I'd guess it's less than 1/10th of a mmm at 30mm. Good enough for my purposes (bookbinding) and I'll use the outside edge more often anyway. I also have an 8x12" tailor's L-square but it's not nearly as legible or well finished as this one.

Updated review 11/21/17. Wanted a small flexible square for lay-out of round logs for rustic building. This is a professional square designed for this type of use. On the back are two 'other' scales with little pictures of rounds with arrows and japanese writing explaining how to use this square. The one scale will instantly show how big a square timber can be cut from the round and will work on logs up to 8 3/8 inches, the other shows the circumference and will scale up to a 3 3/4 inch log. On a american square the outside as well as the inside corner is zero, on this square (except for the 'other' scales) zero is the outside corner. It is 1 1/2 cm. wide, or, 5/8 inch wide by 6 3/8 inch by 13 inches. Very light and somewhat flexible. Because the units (metric) are a base of 10 it is easy to make a scaled down drawing in the field sketch pad then turn around with the same tool and lay out the project. Perfect for this or any small craft work. Cleaned off sticker with a couple drops of Goof Off.

Nice small square. Good quality steel and stays nice and flat. What I expected, nothing less.

Perfect for marking small parts in mm

This square is a great lightweight tool. It's markings are clear and easy to read. The markings are in metric but I don't feel that to be a problem. Itsa good tool for my shop.

I love how flexible and lightweight it is. Unfortunately it's not totally square--it's acute by about 1/32nd of an inch at the full length which is unacceptable for fine work. But it's great for general carpentry work.

It's square but, off by over a mm in accuracy on both legs of the square. It looks like they dressed the edges after it was engraved with the measurement scales and they distorted the scale by grinding away the edge surfaces.