How do you draw straight lines? With a ruler or straightedge. How do you draw perpendicular or angled lines? For that you *could* do it by eye, but a drafting triangle will make the task easier. Not only that, your sketch or drawing will look a lot better too.
A local contractor’s sketch of a deck remodel reminded me of how important drafting triangles could be. Drafting triangles can be immensely useful, but it seems they’re rarely talked about outside of student or design professional circles.
Advertisement
Decking plans are a great example of where a drafting triangle comes in handy, since such a sketch involves a lot of parallel lines and different angles. Sure, you don’t have to add details such as board direction, but it really helps with visualizations and also setting client expectations.
The power of a quick sketch or diagram should never be taken for granted, and it’s even better if the visualization is accurate and looks good.
I’ve been using drafting triangles for more than 20 years. I started with some cheap blue triangles in high school, and they followed me around to college and then grad school. They’re a little scratched up, but I still use them.
A couple of years ago I had misplaced my student drafting triangles and ordered larger Alvin triangles in smoke gray (shown above). Well, I found my student triangles and still haven’t opened my new ones. My new ones are also larger. Maybe eventually I’ll have a drafting table (it’s been my wish for so long!), but right now small triangles work better with individual sheets of paper or my project notebooks.
You can buy a set for under $10, or you can buy them individually. It’s a mistake, in my opinion, to buy one style and not the other. A set usually comes with a 45° triangle and a 30°/60° triangle. The 45° triangle is good for splitting right angles with perfect diagonals, and the 30°/60° is great for isometric diagrams or longer verticals.
Triangles are usually used with a t-square that’s referenced along a perfectly straight table edge, giving you prefect perpendicular lines, but can also be used by eye along another reference, such as the edge of a piece of paper or a ruler mark.
Advertisement
There are some woodworking triangles you could use in a pinch, but moving around a thin piece of plastic over a sheet of paper is a lot easier than a chunk of metal. Plus, the transparency of drafting triangles allows for pencil (or pen) marks to show through. You can also use a fine point marker to draw temporary reference marks right on top, in case you want to space parallel lines a set distance apart from each other.
If this is something you’ve never used before, perhaps file it away under “maybe this will help me one day.” If you have used drafting triangles before, what have your experiences been like?
Buy Now(Drafting Triangles via Amazon)
Buy Now(Alvin 10″ and 12″ Triangle Set via Amazon)
If you’re willing to put in some legwork, you might be able to get the best deals at art supply or craft stores. Craft stores often have 40% or 50% off coupons, making things like drawing templates cheaper to pick up locally than online. If you order online, I’ve had good experiences with Blick. Office supply stores also usually have one or two options available in-store.
With drafting triangles, bigger is not always better. When my student triangles went missing, I thought I could benefit from going with a 10″ 45° triangle and 12″ 30°/60° triangle, but they’re too big to work with on single sheets of paper unless it’s a larger page or you’re sketching on a spacious desk. I’d say that 8″ and 10″ would be better to start with for 45° and 30°/60° triangles respectively, or perhaps even smaller if working space is a concern.
Wayne R.
Prior to using CAD & Visio, triangles were as key to drawings & diagrams as a good pencil. Drafting tables & mobile straight edges are good memories, the stools not so much.
But even just a scale goes a long way to a decent drawing.
fred
Worse memories yet were using those India Ink pens in my K&E drafting set. I never did master setting those little screws right to get the sort of line that I was being asked to draw. The ones on the inking compasses were particularly troublesome for me.
I think it probably was the Space Program – that we’re now remembering 50 years after the moon landing – that spurred technology on. Slide rules and Monroe mechanical calculators that started us into space – were replaced by IBM 360’s – and the computer-age took off.
Wayne R.
As the movie Hidden Figures had shown so well, up until the IBM machine came along, “computers” were people!
Stacey
I had a couple of different contractors estimate a job for me. One gave me a sky high estimate with a nice diagram, the other cheaper guy gave me no diagram with his estimate. When I asked he said he stopped doing them because they would just take the diagram to his competitors! ? Lol, he did a great job though.
Koko The Talking Ape
Back in the day, they used to sell versions of drafting triangles with edges designed for use with ink drafting pens. The edges were undercut slightly so capillary action wouldn’t pull the ink intoa smear. Don’t know if those still exist. I suppose if you were careful, you could just round or bevel the edges of ordinary triangles to get the same effect.
Koko The Talking Ape
And… they do! Amazing.
fred
You mean to say that it wasn’t my lack of finesse – I just might have had the wrong triangles. Gee Whiz – learn something new every day! To tell the truth – I couldn’t use them freehand either.
Koko The Talking Ape
Rule 1: Always blame the tool. 😉
Patrick T
When I was in high-school in the early/mid-90’s, I went to a vocational school to study commercial art (graphic design). At that time, we still did a ton by hand. Our trick was to place strips of masking tape along the bottom to create a small gap. The tape we used was bright white and super smooth…. not like normal masking tape. Worked great. I still have those triangles and they still have the tape on them.
ToolGuyDan
A little HMW tape on the bottom of a triangle can be a lifesaver. Makes it easier to move and also reduces smudging and ink takeup by the triangle itself.
The cost to this advantage is fairly mild; your lines will tend to deform symmetrically instead of unidirectionally away from the triangle if you’re using thin ink that pools. People have preferences; personally, I use pencils or thicker ink and I’d rather *not* be able to tell which side of a line was drawn with the triangle laid against it, so the HMW tape effect is an upgrade.
Stuart
That sounds like a good tip for certain uses, but what happens if you are referencing off the top of a t-square and need to draw angled lines in both directions?
Frank D
I don’t see metric measurements on them … 😉
Stuart
If you’re being serious, I can’t find any good options on Amazon or Amazon UK. JetPens.com has a couple of very small triangle sets, but they’re small and pencil box-sized.
Traditionally, drafting triangles don’t have markings. If I recall correctly, you make a construction line with a triangle and harder/lighter lead grade (e.g. 4H), measure to your endpoints, and then draw a visible line with a softer/darker lead grade.
TonyT
After a quick search, I think you are correct. Here are two on line stores with a variety of drafting triangles:
https://www.duall.com/shop/category/view/294/triangles.html
https://www.draftingsuppliesdew.com/supplies/drafting-triangles
Stuart
Some might have markings for convenience, but all real measurements are probably going to be made with an engineer’s or architect’s scale.
Frank D
Note the 😉
My 36 yr old drafting triangle (which I had to get for school in EU) has mm markings, parallel mm markings, degree angles, segment lines, etc. Plain old ones had mm & cm markings on one side.
Have not seen similar ones for sale in NA, noting that I’m not in design / drafting circles … so they may be around, but have not seen them in office supply stores, back to school sections in stores etc … which should not surprise me, because HD and Lowes don’t even carry rulers that do imperial and metric.
Fazal Majid
I have this Alumicolor aluminum triangle that has metric markings on the short side, and feudal on the longer side:
https://smile.amazon.com/Alumicolor-83012-Precision-30-60-90-Degree-Triangle/dp/B00A6WAW4G/
Wayne R.
“Feudal”, that’s good. I usually go with Metric & Silly.
Jim Felt
Yet another use of that old world word of the day!
Even if kinda futile.
Frank D
Here is my primary design and layout tool …
https://www.conrad.com/p/rumold-triangle-1058-transparent-hypotenuse-length-325-cm-1554375
Malay kumar
Thank you Frank,
I was searching this like hell, as I had seen someone using it, but could not remember name of the company…..
Thanks again….
Koko The Talking Ape
Oh, and I’d suggest the bright orange ones. The gray ones are surprisingly easy to lose on a drawing table.
Brandon
It is comforting to see a post like this today. To this day I require ALL of my woodworking, metal shop, and drafting students draw for 4-5 weeks using drafting triangles, t-squares, and architects scales before I allow them to touch a computer to draw.
Jim Felt
I got nothin’ to add.
But… I carried my high school (portable) drafting board and the triangles and tool set for literally decades. Used them occasionally.
Than one day an exterior house painter was pressure washing some windows on our home and days(!) later I realized somehow (damn custom made wooden windows) leaked under pressure. Directly onto my obviously (bass?) wooden drafting board. Warped the darn thing.
Oh well. All the tools were separate and fine. And I still know exactly where they are.
(PS. I’ve used the same painter ever since that ugly accident in around 1987.)
Altan
I have bought stainless steel ones from China, they are good quality I would say, just the black stamping does not look strong as old US made steel rulers had good stamping for a life, I had a large steel angle ruler from Stanley and gave to a guy who was doing rendering in a bathroom to check the corners to keep everything square for tiling and it got oxidised and I could not read anything on it, after that I always look for stainless steel rulers or similar products.
I would go for this:
https://www.amazon.com/Staedtler-Combination-Stainless-Steel-56632BK/dp/B00279H3ZW/