for a very long time I had thought the STEP DRILL was a gimmick concocted by the sales people of the world.. you know the line "Buy one and get many different sizes" and "comes with free steak knives" so I never took them seriously.
When a friend was putting up a tower, he used a step drill to enlarge some holes in the angle iron (4mm thick)and I heard the dill screaming in protest, which again enforced my opinion they were a 'gimmick'' and I should ignore them. I did notice the holes were very clean and very round when he had finished.
Move forward 4 years, I was stuck at home with an injured ankle and a new found entertainment system (YouTube) was keeping me from going stir crazy. I happened across a series of videos about the conversion of an old Austin Mini to accept the engine and running gear of a Toyota GT4. Its called Project Binky (The name of Deaths horse in the Terry Pratchet Disc world books) and if you feel the need to watch some fabulous construction and bracket making, this series is for you. You also get some wonderful humor thrown in at no extra cost
https://www.youtube.com/results?search_ ... ject+binky
Anyway I digress, in this series about the Mini, they have to fabricate a seemingly endless series of brackets and plates. In all of this they continuously use a STEP DRILL to create the holes in the 2 mm sheet metal. Now the detail they go into and the great camera work shows that each of these holes are perfectly round and leave minimal burs on the hole edge. Okay if it is good enough for the boys from Project Binky then it is worth a real try. I bought my first step drill and started to use it when ever possible for holes in sheet metal or plastic and I have to say this method of drilling is a true revelation compared to the standard twist drill.
If you do not have one, I highly recommend you give one a go, there are a few different ones to chose from, some have BIG size steps all the way up to 30 mm (ideal for holes in project cases) and others have small steps for when you need that 'exact size'.
https://www.bunnings.com.au/craftright- ... t_p0027584
I just today drilled holes in a plastic project case, which has spurred my on to create this post. Holes are round with none of that tearing you can get with a twist drill and the edges are all nice and clean... Also drilled a 14 mm hole in the roof of my little ute for an antenna and again the hole has none of the tearing or 'out of round' you normally get with a twist drill and you have the convenience of not having to change bits when progressing from the pilot hole.
If you have any step drill experiences of tip on their use please add to the thread as I would be please to hear from others on how they get the best from their drills.
