26 Replies Latest reply on Aug 24, 2016 2:01 PM by Scott Larsen

    Show "letter drill" sizes

      Is there a way for SW to put in the callout for a drilled hole that is either and number drill or a letter drill without having to edit the callout? I use the Hole Wizard to create the hole and the letter size as well as the decimal size show up in the browser. But when you go to the drawing and place the hole notation, it only shows the decimal size. Is there a switch I am not finding? Thanks.
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          Charles Culp
          You are not missing a switch, I don't believe this is a capability of Solidworks. I will not preach "good practice", but I believe that this is not included because engineering drawings should not tell the machinist what tool to use, but instead what the end result needs to be. Thus .281±.002 states that there needs to be a hole, but to say to use a letter K drill size, is inappropriate.

          Anyway, like I said, I'm not here to preach, but I believe that is why the software is set up the way it is.
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              Anna Wood
              hw-fstsze is the parameter you want.

              You can update your calloutformat.txt or do what I do for my custom callouts, keep a notepad file on my desktop with all my custom hole callouts set-up for a quick copy and paste into my hole tables.

              At the bottom of the calloutformat.txt file are all the parameters that you can pull from the hole wizard and use in your hole callouts and hole tables.

              See attached example of my hole callout copy and paste file.

              Cheers,

                • Show "letter drill
                  Devon Sowell
                  Hi Anna-

                  I use the same method. Thanks for sharing your file. Mine is to "sloppy" to share
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                      Matt McKendrick
                      I agree with Charles. I never spec a number, fractional or letter size drill. However, I do know what their decimal equivalents are (tooling vendors are always sending me tap and drill size charts) so I never spec a hole that falls in-between drill sizes. (I've seen rookie designers try to do this) This keeps our machinists from making an angry march from the shop back to our office waving a print and yelling. A good machinist will be able to corelate a decimal hole size to a number, fractional, or letter size without further explanation in the print. That being said, I can't imagine it hurts putting the extra detail either, but it is redundant.
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                          David Anderson
                          Charles is correct in that it is not good practice nor proper to specify the tool with which to make the feature. Like Charles, I do not to want to sound preachy but i think its worth noting that it becomes more costly to specify which tools are to be used for manufacture.

                          There are a number of reasons not to specify the drill size and one important reason is the hole size limits are not given and thus the hole cannot be inspected. Some might argue block tolerance applies to the drill size, BUT there is no explicitly stated hole size. You have simply given a drill size an not a hole size.

                          Another reason to not specify the drill is there are metric drills that overlap with english drills. there should be no reason to prevent someone from using a metric drill if it can provide the hole in tolerance given on the drawing. Taking a step further is most machine shops do not have metric drills, they cost about twice as much as an english drill and there are such close size overlaps between the EFU (English Folk Unit) system and the metric system that it makes no sense to have both metric and english drills. Imagine the issue if on a metric drawing one specifies to use a metric drill rather the the hole size.

                          Best,

                          Dave
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                              Matthew Lorono
                              A third reason not to spec drill size (decimal or letter/number or otherwise) is for threads. Internal threads can be roll formed instead of cut. Roll form threads have a much different drill size than cut threads. Specifying drill size for internal threads could actually be putting incorrect information on the draiwng.
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                                    Tom Cross
                                    Have any of you guys ever worked as a machinist or worked in a machine shop other than to clean the floors? The more help you can give the shop, the better. I want to see you roll a #10-32 female thread. That would be real interesting equipment. Yes roll form taps (fluteless) may take a slightly different drill size, but what is wrong with telling the shop what drill to use as well as the decimal size? When you send a drawing to a machine shop to first quote and then to build the part, if he sees a decimal size for a hole, it will cost you more than if he sees a note saying that it is a #7 (.201) DRILL. He automatically knows that he can use a lower cost drill press to put the hole in as opposed to perhaps an expensive miling machine or boring mill because the hole callout only said .201 dia. Is it a bored hole or a reamed hole? Who knows? But by stating that it is a #7 drill, he instantly knows. More information on a drawing has and always will be better for the shop. If some tool maker is insulted because you gave him too much information, that is his problem, not yours.

                                    Tom Cross
                                    (machining, designing and building special machines since 1960)
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                                        Daniel Eelman
                                        On many of our prints, we handle it similar to Tom's method, only we put the decimal dimension first, since we consider that the true specification. Then add the drill size parenthetically as additional information. We actually started this practice at the request of both our in-house machinist and an outside shop. Good machinists double-check that info anyway, but it helps them out during the quoting phase since they know right away what type of processes they are looking at.
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                                            Tom Cross
                                            I would do it that way too, Dan. I just got all carried away venting. Also, the component or dimension that is in parenthesis is a reference item. Like I said, any time you can help the shop, you should.

                                            Tom Cross
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                                                Tom Cross
                                                Dave,

                                                Somewhere in all that education, you obviously missed "understanding the written word". Read my message again! That was not what I wrote! I said "When you send a drawing to a machine shop to first quote and then to build the part, if he sees a decimal size for a hole, it will cost you more than if he sees a note saying that it is a #7 (.201) drill." I thought that was pretty understandable. As I mentioned to Dan, if the .201 is first and the #7 is in parenthesis is fine with me. The key word is "drill".....that's what tells the shop that a precision bore or even reamer is not required and that will always make the part cost less money. When I worked as a toolmaker, my boss used to tell me (over and over) "never work to a half a tenth (.00005") accuracy when plus or minus a sixteenth is fine". That is as true today as it was back in 1960 when my boss said it. That's it. I'm thru on this thread.

                                                Tom Cross

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                                                    Eddie Cyganik
                                                    Tom, David & All,<br /><br />Just my 2¢:<br /><br />The ASME standard is what SolidWorks strives to meet.<br /><br />The ASME standard does state that "manufacturing" means and/or terms are not to be specified on a print. Only the size and tolerance of a feature are to be conveyed.<br /><br />This is one thing: Ø .201 (per block tolerance of ±.005)<br />This is another: Ø .201±.001<br /><br />If this is required Ø .201 (#7), then as Anna stated in the third post, <hw-fstsze> can be used to specify this requirement. Using this, along with Dimension Favorites should satisfy the need if a company deems it necessary.<br /><br />Lastly: I love riding my "high horse" but I did so recently and I have to say it did nothing for anyone but me. And even for me, it only felt good for a while, ...a very little "while".
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                                                David Anderson
                                                Hi Tom,

                                                I'll try to answer your first question, the i will address your other statements/questions.

                                                I started my forway as a machinist in junior high in a coop program. for four years after highschool I worked in construction and built hydroelectric power stations, which required much machining and welding, thus i am a certified welder as well. During this time I also built bridges and concrete dams and ran maintained heavy equipment. For the next 2 years in college i obtained a degree in mechancial drafting and design and i supplmented my income as a machine shop teaching assistent. While pursuing my ME degree, for 5 years, i worked as a machinist nearly full time. I then obtained a job with a presitgious aerospace company, the one that that fixed the hubble space telescope. the machine shop there is of the highest caliber, none better and i had many very high tech parts of exotic materisl made inhouse with no complaints from the shop. i have worked on 4 hubble space telescope instruments and i have many mechanisms and precision optical mounts and structures that orbit you everyday and send data back to earth. these mechanisms worked on install and are still working to this day.

                                                my next move was to a startup as an optomechancial engineer where i purchased, setup and ran the machine and mechanical and inspection shops. all this in addition to my engineering duties. i also did the hiring and firing and i ran the machines when no one else could. in total i purchased close to a million dollars of equipment.

                                                next i was recruited by a college to build out their machine shop from scratch and teach mechanical design and fabrication. i now have a multi million dollar facility with capabilities of full CNC machining, laser cutting, abrasive waterjet cutting, welding, sheet metal and plastic injection molding that i run and manage in addition to my teaching duties. On top of that I have my own very successful mechanical engineering buisness where i design and build precison multimillion dollar mechanisms such as UAV IR surveillance cameras for the US Navy aircraft fleet or solar powered generation stations. All of which I make or have made by outside vendors.

                                                I have worked with machinists most of my life and as a machinist i understand the frustration of drawings being incomplete, ambigous or simply poorly drawn and dimensioned. I make it my mission to ensure my drawings are correct and anyone who works for me is held to the same standard. And being correct means to oonce needs to understand and then apply the stanrds that are in place.


                                                You state..."it will cost you more than if he sees a note saying that it is a #7 (.201) DRILL.

                                                Tom, what are the size limits an inspector is to reference for the hole specified to be machine with this #7 drill?

                                                You state..."He automatically knows that he can use a lower cost drill press to put the hole in as opposed to perhaps an expensive miling machine or boring mill because the hole callout only said .201 dia"

                                                I could not disgree more with this statement. the #7 is ambiguous. What determines the proper machine to make a part are the size tolerances, location and surface finish of the collection of featues.

                                                You state..."More information on a drawing has and always will be better for the shop."
                                                I could not agree more as long as it is not redundent or strays from the ASME standards. Ironically stating the a number or letter drill for a hole is less information since there is no hole size tolerance.

                                                Tom, any advice I give is from my direct experience in industry, working with industry standards and my learnings as bot ha student and a teacher. I adhere to industry standards, because they help remove ambiguity and to ensure my parts will be made right. As you can see, I have many years of direct experience as a machinist and as an engineer. I have walked in both shoes and continue to this day. And i still sweep the floors .

                                                Best,

                                                Dave
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                                                  Roland Schwarz
                                                  re: Have any of you guys ever worked as a machinist or worked in a machine shop other than to clean the floors?

                                                  Been there; done that. Got the drill chart. Didn't need it much, as I had half of it memorized. When I did need it, it was tucked safe and sound in my Machinery's Handbook, often handy for things like rolling threads.

                                                  When I was a machinist, I didn't need some lame engineer to tell me how to do my job. Now that I'm an engineer, I don't tell machinists how to do their job. I just expect them to do it.

                                                  If you need to be told what size drill makes what size hole, you are not worthy of the title "machinist".
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                                          Anna Wood

                                          Devon Sowell wrote:

                                           

                                          Hi Anna-

                                          I use the same method. Thanks for sharing your file. Mine is to "sloppy" to share

                                          I learned this trick from you. You have posted on the topic somewhere along the line in the past couple of years. It was a major Aha!!! moment for me.

                                          Cheers,



                                        • Re: Show "letter drill" sizes
                                          Scott Larsen

                                          Thanks - regardless of all the experts.  I like to be able to specify a fractional or letter drill.

                                          If I choose to use the hole wizard (instead of just extruding or revolving a hole).

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                                        Alan Stoldt
                                        I usually go by the assumption that if someone is asking how to do something, it is because they need to do it that way or want to do it that way.

                                        Why not answer the question and quit quoting Specs or debating small stuff ? Just a thought.
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                                            Eddie Cyganik
                                            Alan,

                                            One of the problems with dealing with issues on a forum is you seldom know how old or experienced a person may be. In this case, all we know is that the original question is from someone with 29 posts.

                                            Specifications are mentioned or referenced because a person may be unaware that one exists. If one follows specifications, then they spend less time reinventing the wheel, so to speak.

                                            Anna provided a possible solution and I reiterated her solution along with the possible use of dimension favorites.

                                            The issue could be closed but we do not know because the original poster has not answered back yet, so we don't know if any of our answers are acceptable.
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                                                My question was asked because the company I work for the fab guys have asked for it. They didn't want to have to look up what drill they can use. They are not machinists. Anna and devon had a good solution. Tom is right also. My experience is 20+ yrs in machine design. I started out as a welder, got training and went in to be a machinist. Then went back to college for design. I have worked a defense job and the machinists said to not tell them what to use. But, I have worked places where they wanted the size of the drill used for taps included in the call out. That was management saying they wanted it. I guess it just depends where you work and what they require. Thanks for the replies. Lighten up.
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                                                  Alan Stoldt
                                                  Eddie,

                                                  I agree. But when people get their feel-goods all upset, it doesn't accomplish a whole lot of anything.

                                                  In my current position I need to deal with some issues like this on a day to day basis. Sometimes it is like being on the Bizzaro World Hrtae ( Bizarro World ), and I may not agree with it, but it is what is required.

                                                  In some of my earlier posts, I had to shift through a load of the same stuff to get to the answer to my question. Some questions were never answered on the forum because of bickering. It happens, I understand.
                                              • Re: Show "letter drill" sizes
                                                Andrew Kieffner

                                                In Solidworks 2012, when you use Hole Wizard to make a hole (ex. #10 thru hole), select Hole Callout to set a dimension for the hole. Click on the dimension itself. In the Property Manager box, there is a tab below the dimension text called "Variables". Select it and select "Description", and select "Okay". A window will pop up saying

                                                 

                                                "Manually altering a portion of the callout text may break that portion's link with the model.

                                                Do you want to continue?"

                                                 

                                                Say yes, and the callout will show up ( ex. #10 CLEARANCE HOLE THRU ALL )

                                                 

                                                Hope this helps!

                                                  • Re: Show "letter drill" sizes
                                                    Matthew Mosher

                                                    This has been perhaps the most useful info in this thread. I was simple making a #36 hole in a part and needed to show drill size for the purpose of this drawing. Sadly Anna's idea did not seem to work (it showed me the decimal dia instead of the drill #). Using the description variable gave me "#36 (0.1065) Diameter Hole" which is closer to what I wanted though I wished it had only given me the #36 part.  Thank You Andrew!

                                                  • Re: Show "letter drill" sizes
                                                    Lenny Bucholz

                                                    Ok here is my experiance as a wood worker, model maker, prototyper, instructor and machinist in many industries.

                                                     

                                                    I really depends on the industry and the the people doing the work!

                                                     

                                                    For woodworking drill sizes are the norm, most only have the drill card with the fraction sizes and most drill cards don't put the decimal size on the slots, also the workers are more artisic than machinist so this helps until they get the experiance to know the decimal size of the common size.

                                                     

                                                    For model makers and prototypers having the drill size helps, really only for speed of getting the project done quickly, but is not nessesary as they have had some sort of machine shop before or have lead people to train them or a CAM package helps in this learning process. I can also see this for the Steel\welding industries.

                                                     

                                                    Now for the trained machinist, They have experiance using either, but the intudstry standard is to put the decimal callout on the hole, not the drill to be used.

                                                     

                                                    If a hole has a decimal and no tolerance and is a drill size from the tap & drill chart we know it's a drill not a ream or a bore, once a tolerance has been added, the drill callout is null and void because it may take 2 opperations to achive your hole tolerance.

                                                     

                                                    That is why notes need to be included as to tapped, press pin, bearings, etc.

                                                     

                                                    Now if you put a .201" hole I betcha 80% of all machinist will ask you are you tapping the hole for a 1\4-20 tap, .313" or 5\16 or O or P for a 3\8-16 or just a thru hole for a 5\16 bolt, we just as machinist.

                                                     

                                                    So know the industry you need to do the drawings for and remember machinist are trained to understand the drawings, there are implied standards to how you have dimensioned your drawings, maybe some should take a course in detailing as either a refresher or because they never have. Remember most machinist are trained in blueprint reading as part of there formal schooling and if they are NIMS certified for sure.