Drafting Text Height 3

[TJK1]

I have been asked to review our companies new drafting standards manual. We use AutoCAD and generally use either B-size or D-size templates in AutoCAD to create the drawings. We always print out our hard copies as B-size prints. The guy writing the manual specified that text should be created at .12 inches high in AutoCAD when creating a B-size drawing and at .14 inches high in AutoCad when creating D-size drawings. When we print the D-size drawing out on a B-size piece of paper, the text actually measures only about .07 inches tall. To me that seems kind of small. Is there an industry standard for minimum text height printed out on a B-size (11x17) inch piece of paper? Also, I like to draw everything 1 to 1 and scale the drawing border to what ever fits nicely over the drawing, but the drafting department says it more important to keep the borders consistent and scale the drawing to fit the border. Which way is more standard? We state on our drawings that they conform to ASME Y14.100-2000. Also our drafting manual states that you need many different layers for solid lines, hidden lines, text, dimensions, the border,etc. Is there a real requirement for so many layers?

 

[KENAT]

TJK,

don't have time for a full answer but:

To the standard you reference if I remember correctly 3mm is the minimum text height regardless of drawing size and it doesn't say anything about printing out at reduced scale. We face the same problem so standardized on .15" text so that it's legible on B size print of E drawing. Of course it looks stupid on B size drawings. My solution of printing drawings the way the designer intended isn't well received.

If I understand correctly your drafting department is correct. I believe the drawing border should be consistent. There's an ASME spec referenced by 14.100 that details this.

The layers thing is probably specific to your CAD system, I don't think the ASME standards will say anything about it.

KENAT, probably the least qualified checker you'll ever meet...

 

[ewh]

I agree with KENAT. As for layers, They are not covered by any industry standards as far as I know, but entirely dependant on the company DRM.

 

[TJK1]

I was not able to find the 3mm minimum text height referenced anywhere. Does it apply to hard copy prints (any size A through E)?

 

[KENAT]

TJK, if memory serves it is in Y14.2M Line conventions and Lettering.

I no longer have access to a copy of this, only an old copy of ANSI Y14.2M-1979 which appears to be different from what I remember of the newer standard.

It would apply to hard copy prints at the same scale/sheet size as drawn I don't recal it making the distinction between hard and e copy. Except for some allowances for micro-filming I don't think the standard makes allowance for scaled down prints either.

Again my position is that for 'official' purposes an E size drawings should be printed at E size and so on. If you choose to print a reference copy on a smaller size it's up to the printer to put up with the consequences.

Note, the 3mm is a minimum, you can go larger but going larger can have penalties for instance on dimension spacing and the amount of space used. Our .15 text is usually legible even on a B print of an E drawing.

FYI this question may have been better in Drafting Standards, GD&T & Tolerance Analysis

http://www.eng-tips.com/threadminder.cfm?pid=1103

KENAT, probably the least qualified checker you'll ever meet...

 

[Finethread]

From ASME Y14.2M - 1992

Drawing Title, size CAGE code, drawing number, revision
Sizes D,E,(and larger) .24" Min.
Sizes A,B,C, .12" Min.

Section and View letters, Zones
.24" Min. all sizes

All other characters
.12" Min. all sizes

Block Headings
.10" Min. all sizes

 

[TJK1]

Thanks Finethread. I do not have Y14.2 and so I was wondering, if we draw on an electronic AutoCAD format of a D-size sheet of paper, but then plot the image on a B-size (11x17)piece of paper would we need to follow the guidelines for D-size or B-size text size requirements, as specified in Y14.2?

 

[Finethread]

I can't find any mention of guidlines for reproductions.
If your company's practice is to print everything out on B size, then I would increase the font size on the D's. The numbers I provided are stated as a minimum so you could make the font used on D's larger to make them easier to read when reduced. The whole point after all is legibility.