

📐 Elevate your craft with precision that won’t quit—because your projects deserve the best.
The Johnson 400EM-S 12" Combination Square is engineered for professionals who demand accuracy and durability. Featuring a CNC-machined cast zinc head, a stainless steel blade with permanently etched dual graduations, and an Auto-Lock blade assembly, this tool delivers precise 45° and 90° measurements, miter cuts, depth readings, and leveling. Built tough with a chip-resistant finish and a hardened scriber, it’s the ultimate all-in-one measuring companion for serious craftsmen.


















| Brand | Johnson |
| Color | Black |
| Graduation Range | 1/32 Inches |
| Material | Stainless Steel , Zinc |
| Product Dimensions | 12"L x 5.5"W |
| Style | 420EM Inch/Metric Metal |
J**A
Love this combination square!
Love that is stainless steel so it won’t corrode in humid Florida, love that the numbers are etched and won’t rub off, love how it’s a very solid hunk off metal and not some plastic Tonka Toy piece of junk, love how it has both inches and metric, and love how my table saw blade is finally square!! And all at a reasonable price. This is the one to have!
G**Z
Really a great value.
I am not a tool snob, but I do like quality tools. I already have a really nice PEC square that is built/rated to very high specifications. I thought I would buy this just to have around when I needed something for measuring lumber (2 X 4 ) without breaking out my really nice square. When I opened the package I was really impressed with the weight of this tool. It does not feel like a cheaply made tool at all. Then I did the test where you take the square - draw a line about the length of the square, then turn it around and duplicate the line. To my surprise this square is every bit as square as my PEC! If you are new to woodworking, I would suggest picking this square up. I am going to treat this tool as if it cost me 100 bucks just because it is so well made. I wish all low cost tools were of this caliber of quality.
S**B
Could be better, but better than any other metric version on Amazon.
I really needed a metric version of this tool and originally all I could find were these horrible green ones that came in Chinese packaging. They were sharp and damaged all over. Compared to those this one is golden. It still seems a little rough around the edges, but is much better quality, and the machining is smooth. There is still the occasional small gouging, but it is finished over and not sharp to the touch. The locking mechanism is very cheap though. It really drives down the quality of this tool. The ruler also has edging issues where it is finished to much casuing the lines to have been worn off.
J**B
As described
Works well. Square seems accurate. I don't use for high precision work so good accuracy for my purposes. I would buy again.
A**N
Good Tool Great Company
I recently purchased the tool and it is square and very good quality. Unfortunately my unit had a slight issue in that the ruler would not hold tight due to the lock nut and spring combination. I contacted the company and they immediately issued an RMA, a shipping slip and promptly returned a brand new unit. I would not hesitate to buy from them again, the fact that they honor their warranty and provide up to date communication along with a good sturdy, quality tool makes them an A+ value brand!
R**.
They work great
Perfect replacement for my broken Stanley square
D**D
Excellent Quality and Value. Made in the USA
I purchased this to replace an old Johnson that had rusted out just hanging in the garage and the square was plastic. I didn’t even realize how much of an upgrade this turned out to be. The ruler is stainless steel, the square is zinc and has a hardened scribe built into it. On top of all that it’s made in the USA. What a pleasant surprise.
F**S
Nice square!
Quality
Trustpilot
2 months ago
1 week ago