Significance of the symbol 1

• Jul 25, 2023

1
• #2

Garland23

Mechanical

Dec 4, 2021

99

It's not a standardized symbol (that I know of). So check the notes or title block on that drawing. There should be a legend that explains what that means -- perhaps a "critical dimension"? Or a dimension that needs to be reported by QA on a check sheet?

 

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• Jul 25, 2023

• #3

Doug Hunter

Automotive

Jul 24, 2023

68

Ditto Garland23.

 

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• Jul 26, 2023

• #4

cowski

Mechanical

Apr 23, 2000

8,155

The part must be machined under the light of a 1/2 moon to the proper size as indicated by the runes. May Mazak have mercy on you. </s>

 

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• Jul 27, 2023

• #5

BiPolarMoment

Mechanical

Mar 28, 2006

617

cowski said:

The part must be machined under the light of a 1/2 moon to the proper size as indicated by the runes.

Click to expand...

I thought it was indicating that it was acceptable to be machined in either full light or full dark.

 

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• Jul 27, 2023

• #6

Burunduk

Mechanical

May 2, 2019

2,338

Guys,
"The drawing should define a part without specifying manufacturing methods."

 

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• Jul 27, 2023

• #7

BiPolarMoment

Mechanical

Mar 28, 2006

617

Now who is living in fantasy?

 

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• Jul 30, 2023

• #8

Wuzhee

Automotive

Jul 12, 2022

270

Burunduk,

What about surface roughness? You CAN specify exact methods of required machining.

 

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• Jul 30, 2023

• #9

Garland23

Mechanical

Dec 4, 2021

99

Wuzhee, with roughness you can indicate the final specs of the surface (whether material removal is required or prohibited, etc.). But one could say that that still doesn't specify the actual manufacturing method.

 

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• Jul 31, 2023

• #10

Wuzhee

Automotive

Jul 12, 2022

270

I disagree with the second sentence. ASME allows for calling out specific manufacturing. If I want it that way, there's no workaround for that in manufacturing imho.

 

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• Jul 31, 2023

• #11

Burunduk

Mechanical

May 2, 2019

2,338

In "should define a part without specifying manufacturing methods", the key word is "should".
However, what advantage is achieved in requiring "Lapping"? If the same surface roughness can be achieved by several processes, why limit your supplier to only one? Also how will adherence to this process requirement be examined and confirmed during the finished part inspection?

 

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• Jul 31, 2023

• #12

Wuzhee

Automotive

Jul 12, 2022

270

If I would design a thing similar to a combustion engine with a cylinder, piston, conrod etc, and I want an oil containing surface, I'd put "honing" in surface symbol without second thought. In the auto industry it's common practice but if my contractor is not familiar? Then I have to specify because many other techniques wouldn't provide me that required surface for my engine-like thing. Just one example.
There's the C for concentric texture. Linear grinding can't make circles. Or if mirror polish is a requirement. I can put Ra0.2 there but milling also can make Ra0.2 so I think it has it's place.

 

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• Jul 31, 2023

• #13

Garland23

Mechanical

Dec 4, 2021

99

About lapping, etc.-- true. As Burunduk mentioned, that's where the word "should" is important, rather than "shall."

 

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• Aug 1, 2023

• #14

pmarc

Mechanical

Sep 2, 2008

3,162

From the same paragraph that Burunduk quoted (4.4.e in Y14.5-2018):

"However, in those instances where manufacturing, processing, quality assurance, or environmental information is essential to the definition of engineering requirements, theinformation shall be specified on the drawing or in a document referenced on the drawing."

 

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