Finish symbol on drawing 1

[jerry1423]

I have a finish symbol on a cylinder, and a finish symbol (of the same roughness) on the flange face that is perpendicular to the cylinder. There is a fillet that joins the two surfaces.

Can it be implied that the fillet will be the same surface finish of the two other machined surfaces, or do I need to add a finish symbol to it also?

This is for a machined casting.

 

[NomLaser]

I would add a symbol to any surface that you want it to be specified on. It eliminates any confusion and you will be more likely to get what you wanted the first time around.

 

[TVP]

No, it cannot be implied that the fillet will have the same surface roughness unless you specify it.

 

[KENAT]

Sometimes, it's appropriate to specify an all over default surface finish, and only uniquely identify surfaces that differ.

Otherwise TVP & Nom are about right, if you don't explicitly spec it you aren't speccing it.

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[jerry1423]

Thank you all for your replies, and clearing this up.

 

[ewh]

I don't find it at all clear... I will have to look over the current standards, but I am pretty sure that any surface in between the same callouts default to that callout. I am also sure that I will be corrected if the standard has changed, which I welcome.
According to the Machinery's Handbook Twenty-First edition(which references ANSI Y14.36-1978), "Areas of transition, such as chamfers and fillets, shall conform with the roughest adjacent finished area unless otherwise indicated."
Therefore, if the surrounding surfaces have the same finish requirement, then the transition surface will also have that finish requirement.

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]

 

[KENAT]

Oops, looks like I may have spoken out of turn then, appologies.

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[ewh]

No you didn't... I was hoping you'd have the current standard to quote, though... my machinery's is a bit dated. ;-)

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]

 

[PeterStock]

I read through the surface finish section of my Machinery's Handbook (25th edition) and could not find a statement about areas of transition. Where in 21st edition is that statement?

Peter Stockhausen
Senior Design Analyst (Checker)
Infotech Aerospace Services

http://www.infotechpr.net

 

[ewh]

Page 2392, very last sentence.

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]

 

[KENAT]

Well I don't have 14.36, my manufacturing guys might have a copy but I'm a bit busy to go check. My 27th edition of machineries which references ASME Y14.36M-1996 has the same wording as yours (page 733).

I also have the genium & global manuals but they are too thick to look through for other peoples problems;-).

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[MALK]

If it can possibly be mis-read I would define exactly what I want and not rely on the reader having as good or better understanding of the standard than I do.

 

[NomLaser]

I agree with Malk. If you leave it to be interpreted then you leave yourself open for nonconforming parts. Better to be perfectly clear on your intentions.

 

[ewh]

Lack of education relative to the standards that you have to work to is no excuse for fabricating parts that do not pass inspection. The VERY first time you ASSUME something other than what the relevent standards indicate, you should be corrected.
While I agree that adding the extra symbols will eliminate any confusion, I would rather eliminate that confusion through education. Yes, you may get non-conforming parts, but you will also get better educated workers. Of course, in todays economic climate, getting parts out the door is far more important than investing in your workforce.
All it would take is a couple of whacks on the head, and they won't make that mistake again!

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]

 

[NomLaser]

EWH, I agree to the point that it is far better to educate your own workforce but what happens when you suddenly have to send that part to China, for example. I doubt that you are going to be able to educate someone outside of your own company.

 

[ewh]

China is a whole 'nother can of worms!
My response was aimed more at work done in-house. Other people's employees are their problem, and all you can really do is as you suggest, or start rejecting parts if you have the luxury of time.

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]

 

[looslib]

The advantage of using standards to define how something is to be done is that others SHOULD have the reference that you are asking them to build your parts to. It is their responsibility to make the parts to your standards when they agree to do the job.

Yes, if you have the luxary of time (and money) you can reject the parts until the supplier delivers what you have spec'ed on the drawing.


"Wildfires are dangerous, hard to control, and economically catastrophic."

Ben Loosli

 

[ewh]

time = money

"Good to know you got shoes to wear when you find the floor." - [small]Robert Hunter[/small]

 

[PeterStock]

I reread my 25th edition of Machinery's and found the reference to transitional areas.

Peter Stockhausen
Senior Design Analyst (Checker)
Infotech Aerospace Services

http://www.infotechpr.net