-----> How Do I Do This?

If someone gives me a drawing to detail out that has blind tapped holes in it....how do I determine what size hole and thread he used in his design from the original file with no details on it?

Thanks

John

I would have to say "you can't".

I would have to say "you can't".

I 2nd that!

Well, maybe I'm being a neanderthal here, r14 doesn't have all the fancy tools the newer systems have but....

If you have the original design drawing then from the side view simply do the DIST command then select each endpoint of the outer tapped lines to get your tap size. Of course you'll need to determine if the tap is course or fine thread. If you're lucky and the drawing was done in great detail then the inside tapped lines would tell you the minor diameter of the tap and with that information you consult the "Machinery Handbook" or other reference material to determine courseness.

Am I showing my age here or what?

would you trust a person to draw to size if they can't put the information down in text form in the first place?

would you trust a person to draw to size if they can't put the information down in text form in the first place?

Well, it hinges on the person, organization, methods etc. A design doesn't have to have that information attached to it if the system is set up to not need it. Perhaps through automation. So let's say a designer is using a "tap" block that is constructed with "great detail". The outer lines measure .2500 and the inner lines .1960 we know it is a 1/4-20 UNC. If the inner lines are .2110 we know it's 1/4-28 1/4-28 UNF

So if the organization uses a TAPC block or a TAPF block the designer select one or the other and there is no need to specify via text the courseness of the thread. Yep, I know there are other ways of accomplishing this but it's worth a shot to simply perform a DIST command.

That is exaactly what I have done in this situation...I just found my ID and OD and referenced my screw selector slide card charts and was able to determine all of my holes and screw sizes.

Thanks again for the help

John

Well, maybe I'm being a neanderthal here, r14 doesn't have all the fancy tools the newer systems have but....

 

If you have the original design drawing then from the side view simply do the DIST command then select each endpoint of the outer tapped lines to get your tap size. Of course you'll need to determine if the tap is course or fine thread. If you're lucky and the drawing was done in great detail then the inside tapped lines would tell you the minor diameter of the tap and with that information you consult the "Machinery Handbook" or other reference material to determine courseness.

 

Am I showing my age here or what?

That would have been my first step considering there is no hole/thread call out. Assuming of course that the drawing is 1:1 and the person drawing had some decent accuracy/drafting.