12 Replies Latest reply on Apr 18, 2008 2:11 PM by Matthew Lorono

    Dimensioning Holes

    Lamonte Bell
      What is the correct callout when you have a hole for example that is going thru a tube. The hole goes thru one side but not all the thru and out the other side. So should this callout be "THRU" or "THRU ALL" or none of the above.
        • Dimensioning Holes
          Eddie Cyganik

          Lamonte,

          In this case, I have always explicitly called out the requirements as:
          Ø.250 THRU ONE WALL

          Again, no interpretation necessary.
          • Dimensioning Holes
            Suresh B
            Lamonte,
            I would say 'none of the above', but like Eddie mentioned you can be very specific so there is no ambiquity for the end user while reading the drawing
            • Dimensioning Holes
              Edward Sine
              LaMonte,
              The correct way to call out you hole is 'Thru' only.
              My information and what I use come from Global Engineering Documents.
              We used this book for industry standard's and it is also approved for Department of Defense. This book is ASME Y14.5M along with many other ANSI standards and also has ISO information. If your interested in getting a book for yourself this one ran about $225 ten years ago. It is called Drawing Requirements Manual. But it is packed with alot of information and examples of how to prepare your final drawings. When I did contractor work on the AH-1W Super Cobra. This is the only book we went by as it covered all the requirements for D.O.D. If you have any reason to think your manufacturing department will screw it up even though your drawing is correct. You might want to give them a cross section. But your correct to call it out as thru.
                • Dimensioning Holes
                  Eddie Cyganik

                  Edward,

                  The term "THRU" is used in many ways; (and abused)

                  THRU can mean "thru everything".
                  THRU can be omitted, which again means "thru everything".
                  THRU can mean "thru only what is shown".

                  THRU ALL is still used. (Although incorrect per ASME)

                  Specifying a term "to mean one thing" and "to be used in a consistent manor" is acceptable.

                  We use THRU ONE WALL to mean exactly what it says, no need for interpretation, no confusion and it can be used in a plan view (hole appears as a circle) where holes are supposed to be called out.

                  Our method is legal and it does not violate any approved standards or specifications.

                  Lastly, the Drawing Requirements Manual you refer to is a good reference, as a matter of fact I've got a Seventh Addition on my shelf.
                  I use it as a reference but it is not gospel.
                    • Dimensioning Holes
                      Edward Sine
                      All I say in my defense is.
                      There are industry standards in place. Period!
                      We have always followed them when I work on D.O.D. drawings and we have followed them when I worked on the commerical side. Everyone always has a better solution and that is why companies, countries and leaders in the industries set these standards for others to follow in print by working with publishers like Global Engineering Documents. This is not the only book they have published on standards. If someone wants to say and do it; their way, in their own shop. It is no skin off my back. But when the finger pointing start because a ton of money has just been wasted making new parts. At least Lamonte would have a leg to stand on.
                        • Dimensioning Holes
                          Eddie Cyganik

                          Edward,

                          You are no different than I am when in comes to standards. We both strongly believe that standards are there for a number of reasons and that if we follow them, then we are doing the right thing and we have them to back us up.

                          If anyone were to follow my suggestion, including LaMonte, they would have a leg to stand on.

                          Quoted from Global Engineering Documents: Jerome H. Lieblich

                          The question most often asked about the use of this DRM can occur in any section being asked about is "What published government or industry specification or standard was the information or procedure that is described in this DRM extracted or quoted from?" The answer is most often "NONE".

                          There is more to this comment in the attached image.

                          In general, my interpretation is that there are many areas in existing standards (like ASME Y14.5M) that are vague or illustrate by example only. The bottom line is to produce a proper drawing; it needs to be Clear, Concise, Accurate and shall not be subject to more than One Interpretation. Therefore if you meet these criteria and do so on a consistent basis, you do not violate anything and you do have legs to stand on.
                            • Dimensioning Holes
                              Paddy Rose
                              When the guys in the shop can barely read, let alone read a print, national standards may slip a notch or two in importance. More than once my boss has told me that a print I had done was "...legally to standard, but needed to be Idiot-Proof."

                              So, I say "Thru one wall."

                              (Although, in my heart of hearts, I want to spell it "Through.")
                                • Dimensioning Holes
                                  Eddie Cyganik

                                  Paddy Rose,

                                  This is exactly the point I was trying to make.

                                  "Ø.500 THRU ONE WALL" cannot be interpreted any other way.
                                  (It is also legal & acceptable.)

                                  As far as the spelling goes, well, THRU is the legal abbreviation per ASME Y14.38 - Abbreviations and Acronyms.
                                  • Dimensioning Holes
                                    Dan Riffell
                                    I see a lot of people get up in arms about what standards should be used in engineering drawings, and I find it a bit silly.

                                    The real issue is the drawing or drawings themselves. You should always ask yourself some simple questions when you think you are done detailing them. Do they communicate your design accurately? Are they unambiguous? Do they contain all of the information that someone needs to manufacture the object (assuming your drawing is for manufacturing purposes)?

                                    If you can answer these simple questions each time, then your drawings will be good (generally) regardless of whether or not you have followed ASME Y14.5 or whatever standard tickles your fancy.

                                    I've done business with plenty of local and international engineering firms and manufacturers, and one thing is consistent across the board: everybody has their own standard of what is "correct". If you follow Eddie's advice that "The bottom line is to produce a proper drawing; it needs to be Clear, Concise, Accurate and shall not be subject to more than One Interpretation" everything will (generally) work out seamlessly.