Is it really risky to use chipping bit to enlarge a hole?

Question

The second stick from top is the "breaking" bit as locally called. Is referred as chipping spear hexagon here.

The bottom left white dust covered one is the "puncturing" bit as locally called is the drilling bit. Sorry for low resolution. It has similar flat triangle tip like the big rusty masonary bit above of it. Referred as drilling bit here.

I once had to drill RJ45 holes through a concrete wall but the rotary hammer and a masonry drill bit wasn't long enough so I had to take measurements from both sides and drill from the both sides.

The holes weren't large enough, missing the mark by less than 5mm so I decided to take the pointy chiseling bit and hammer mode to enlarge the hole. First hole was chiseled from one side only and made a bit small but noticeable hole crack from the other side.

The second time, I chiseled from both sides and the hole looked perfect with only a small bit of a crack looking line from one side but that was it. The chiseling bit got stuck a little so I decided not to force the rotary hammer so I removed the bit and slightly tapped it's rear end and it came out without much of a problem or any cracks.

The only time that was a "Just Works" moment was when I didn't have a extension cord so I couldn't drill from both sides and the my family told me to use the hexagonal chiseling bit because it was longer. I told them it isn't really for drilling but they insisted so I "accidentally" made a large hole on the other side of the wall and the chiseling bit got stuck. I had to remove it like a hacksaw by hitting it from the both sides with a hammer which worked decently when it came to removing the bit and "enlarging" the hole a lot more.

What I am wondering is, Is this makeshift method of enlarging holes with a chiseling bit something that people do when in hurry and with a missing drilling bit or I was extremely lucky to do it decently? In Turkey we use brick and mortar construction with concrete and bricks everywhere so I also wonder if it's something that can be done on drywall as well since some places have drywall ceilings in this country.

Answer 1

As best I can tell from the small picture, the top two bits (identified with red arrows) are for breaking up concrete/brick (hence them being called "breaking" bits), while the bottom two bits (identified with green arrows) are for drilling holes (hence "puncturing" bits).

In my opinion, you were indeed "lucky" to have been able to enlarge a small hole with one of the "breaking" bits without causing additional damage to the concrete that you were drilling in.

There are many comments suggesting that you should "just get the right size bit", and that is the right answer 100% of the time. Except when it isn't. Not everyone has access to the vast quantity of tool options that I do here in the US, so I realize that "the right tool for the right job" isn't always an option. Sometimes you do have to make do with what you've got, and, in your case, it seems that you've gotten away with using the wrong tool.

It is highly recommended that, in the future, you try to find the correct size bit for the job at hand. If you cannot find one, or cannot afford it, you'll just have to make do with what you've got. You've got some experience now, so if you have to use the "wrong" tool again, at least you've got a feel for what to do and how to do it.

For future reference, in English:

• The bottom two bits would be referred to as "twist bits". The extra little wings at the tip identify these specifically as "masonry twist bits". The wings actually break the concrete, while the flutes (the twisted part) pull the broken concrete out of the hole.
• The next bit up would be called a "chisel bit" and it's designed simply for breaking up masonry (concrete, brick, etc.). You can use it for cutting masonry by hammering along the cut line. You might find it to be difficult to do so accurately, though, because the hammering action of the drill makes it hard to place the chisel accurately along the desired cut line. If a rough cut is acceptable, then this will certainly do the job.
• The top bit is one I have never seen (in my admittedly limited concrete drilling experience). I would consider it a "pointed chisel", and would expect it to work similarly to the "regular" chisel bit below it.