This is a speed square or "half" of one anyway! These are typically used by carpenters, fabricators, or just anyone who needs to put material together and needs it to be square. As a heavy duty diesel AG tech I use one from time to time. I also run a welding business on the side and that is where I mostly use this speed square. Specifically when building pipe fence.  I like this because it easily sits over already existing welds and quarter round trim or anything that might be in the way. 

I made the ones pictured above out of light grey PETG, normally I use a bright orange color (so they are easy to see) but I had some light grey that needed to be used up. You can see in the pictures I started to color in some of the marks with black marker but personally I do not like this look. Maybe if one had a fine tipped marker it would look better but wanted to go ahead and include the picture. 

• PETG seems to hold up well as long as you don't immediately put it against something boiling hot from being welded on (I've found with the lower portion of the square missing it works better for welding I can check right after welded or tacking and don't have to worry about being close to what I just welded on and melting my speed square. 
• I chose PETG and used around a 25% infill since I use the item outside and around UV light from welding. I have had no issues with these (of course over time I have dropped things on and broken a couple) but that's bound to happen. 
• This item can be printed without support ( Depending on what way it's rotated in the slicer) the one in the pictures was printed without support. 
• I have also printed a coupler of these using ASA which have been just as good if not better than the ones printed in PETG 
• If you're like me you will print several of these and throw one in here one in there ect. I have two or three in the garage, one in this truck, one in that truck, a few at work, a couple in the service truck, ect. 
• If you are not a fan of the “half” speed square I will be uploading a large 6" and small 3" square with roughly just a ½" out of the lower corner to allow for a weld clearance. 
• In the pictures you may notice my print quality is not the absolute best. That is due to printing it on my older ender 3 V3SE since I already had the filament on that printer. Between it giving me trouble in the past and not putting the filament in a dryer beforehand I have learned to accept that I am not getting a “perfect” print off of it. 
• I was not out building a pipe fence at the time I decided to post this, nor do I have any reel good pictures of this tool in action so there is a picture above of it being used against the wall of the china cabinet. 

If anyone has any feedback or questions please let me know, I like constructive criticism and will answer any questions. 

Thank you for your time considering this post and print!