Can a drilled hole be enlarged by a drill bit? Is it advantageous? Why is it only reaming or boring tool is used to enlarge drilled hole?
Sure, it's the same principle as drilling a small pilot hole, followed by a larger hole. However, a reamer will, generally, provide a more accurate hole with a better surface finish.
Add to Robert Hafley's reply: The amount of material removal through reaming and boring is relatively very small to get better finish, precision and accuracy. Drilling by a larger drill is to only to enlarge the hole.
Thanks robert and arumugam sir, generally we have drill bits upto size 25 mm practically so i think to enlarge hole more than this size we have to use reaming/boring tool.
A step bit could be an option - particularly for enlarging a hole in sheet metal (and of course a tapered reamer could also be used if the hole is too far from the edge).
If you have access to a CNC mill. You could use an endmill to enlarge the hole.
The take away from this is it depends on the required size and precision required, as well as the tools you have available. Since you are talking about holes larger than 25 mm, Edmund's CNC mill suggestion, using either an endmill or a boring bar, is a good one, assuming you have the equipment available.
As with previous answers it is all to do with tolerances. You can use a round file if you wish, but the hole will not be in tolerance, unless you don't want it to be. Equally an H7 reamer may not be useful if you want an H9 hole. A boring bar is, again, tolerance constricted. So to answer your question, well there are lots of answers.
There are multiple factors that may influence the choice or the need to enlarge and existing hole. I can speak from the perspective of drilling for oil. Prominent factors include changes in well plan while drilling or the formation type encountered at a certain depth.
- Badges
- Science topic
- Similar topics
- Econ
- Manufacturing