quotation depth blind holes

[Tommaso Bari]

Good morning, everyone.

I would like to ask the most experienced a simple question, how do you quote the depth of a blind hole? for example, a hole to be masculine.

I found myself in front of two distinct situations:
1. the quotation according to regulations, which quotas the depth from the beginning of the hole until the end of the cylindrical part, without therefore considering the conical zone of the tip.
2. the quotation up to the tip of the hole including the conical zone, in particular this was taught to me in the company with as motivation the comfort in the programming of the machine tools, which reset the tips on the top.

as said I would like to hear the opinion of someone more experienced on the issue, since mine is the first job in a technical office and so I only saw a company reality.

Thank you.

 

[DrBarde]

Good morning

personally I have always quoted without considering the conical area.

 

[Vittorio]

Good morning
I have always quoted the total depth including the conical part
1) for convenience of cnc operator
2) to avoid performing a deeper hole than required

It seems to me that the legislation says without considering the conical zone.

However if there are no particular attention.. both methods are fine.

 

[wert]

separate regulations, put on the drawing the depth considering also the conical zone, then does not allow to perform any control of the depth of the hole, if not sacrificing a piece to cut it in correspondence of the half-hole. if really so useful for the purposes of cnc programming, any workshop manual (me comes in mind the white) allows to easily calculate the lower cateto of the triangle (without knowing by memory the trigonometry) to obtain then the quota that sums the cylindrical part to the conical one.
since the cad offers it free, I would put both odds, with that of the total depth in parentheses; solution that saves goats and cabbages.

 

[Vittorio]

if really so useful for the purposes of cnc programming, any workshop manual (me comes in mind the white) allows to easily calculate the lower cateto of the triangle (without knowing by memory the trigonometry) to obtain then the quota that sums the cylindrical part to the conical one.

right observation.

on cnc no problem, all cams ask you if you want to consider or not the conical part.
the operator however resets the tool on the tip.
on a traditional drill the direct share is more comfortable without making additional calculations.
I agree.

every case must have his attention.
For example in my case, I happened that the tip had not been sharp at 118° but at 90° and the hole was made deeper by interfering with a circuit below.
the cylindrical part remains less profound without causing damage.

 

[LaboratorioDieci]

since the cad offers it free, I would put both odds, with that of the total depth in parentheses; solution that saves goats and cabbages.

It would not seem to me the best solution, since then the performer could find a difficulty of interpretation. I personally like the option more @vittori : share of the useful part unless the risk of going to damage what is ahead of the hole.

 

[wert]

It would not seem to me the best solution, since then the performer could find a difficulty of interpretation. I personally like the option more @vittori : share of the useful part unless the risk of going to damage what is ahead of the hole.

if one knows the design, there is no difficulty in interpretation. the quota in brackets is auxiliary and can be useful to some actor within the process, while the one without brackets, is that to be respected (if it has no tolerance, apply general tolerances) and, consequently, to be checked. I repeat, each dimension must be controllable with tools more or less common use and, possibly, without destroying the pieces. the fact that one can make a hole with a tip at 90° instead of 120° leaves me quite perplexed... Perhaps this happens when you have to make a prototype piece, with tools of luck, but if you have to make series, things must be done as you must and quality control must be able to control them.

 

[Tommaso Bari]

thank you all for sharing your experiences.

I agree with the concept of depth control, if this is to be respected, we must follow the legislation so that we can verify it during a quality control, and I agree accordingly with what is said by @laboratoriodie in case of possible damage of other components

I personally believe that in the company from me you prefer the quotation conical part understood because we do not have cam tools, in most cases the size that must be respected is more the length of the possible thread (many times are precisely threaded blind holes).
in some old drawings in the company I have also seen that the depth of the preforum is not even quoted, is indicated only the thread, then the operator knows how to calculate the complete hole

p.s. I did not specify that my company does not work bills, so the machine operators " always find the same pieces" we say

 

[Marco F inox]

if one knows the design, there is no difficulty in interpretation. the quota in brackets is auxiliary and can be useful to some actor within the process, while the one without brackets, is that to be respected (if it has no tolerance, apply general tolerances) and, consequently, to be checked. I repeat, each dimension must be controllable with tools more or less common use and, possibly, without destroying the pieces. the fact that one can make a hole with a tip at 90° instead of 120° leaves me quite perplexed... Perhaps this happens when you have to make a prototype piece, with tools of luck, but if you have to make series, things must be done as you must and quality control must be able to control them.

in a drawing, to quote the diameter of the hole and the two depths, toe included and not, forces the operator to calculate the cutting angle of the tip, which is absolutely wrong.
it is always better to quote the depth of the cylindrical part, depending on any thread.
the operator to the program will always be able to adapt, but in the technical design it is always better to eliminate preferences.

 

[meccanicamg]

Good morning, everyone.

I would like to ask the most experienced a simple question, how do you quote the depth of a blind hole? for example, a hole to be masculine.

I found myself in front of two distinct situations:
1. the quotation according to regulations, which quotas the depth from the beginning of the hole until the end of the cylindrical part, without therefore considering the conical zone of the tip.
2. the quotation up to the tip of the hole including the conical zone, in particular this was taught to me in the company with as motivation the comfort in the programming of the machine tools, which reset the tips on the top.

as said I would like to hear the opinion of someone more experienced on the issue, since mine is the first job in a technical office and so I only saw a company reality.

Thank you.

perfect, you answered yourself.
all share in norm.
only the workshops that do not know how to use the breast and the little thing must have quoted from the tip systematically.
that the conical part is more or less long does not affect anyone, because it is the thread or the lamato/halese section that serves for mechanical purpose.
If you have to do a plumbing with deep and intersecting holes, but you don't want them to sink your walls, that's what you have to say... because the goal is not to wash the walls or travases.