Hope this is the right place to ask this question - I am new to this.

A recent dispute with a cusotmer over a feature regarding a radius has prompted this post. The Feature is called out on the print as "R", the customer insists this means "Full Radius". I have looked through ANSI and do not see where it is specifically difined as such. Any input would be appreciated.
Thnx

Hope this is the right place to ask this question - I am new to this.

A recent dispute with a cusotmer over a feature regarding a radius has prompted this post. The Feature is called out on the print as "R", the customer insists this means "Full Radius". I have looked through ANSI and do not see where it is specifically difined as such. Any input would be appreciated.
Thnx

"Full radius" is still just radius. Is he trying to say the "full radius" is the diameter?
http://dictionary.reference.com/browse/radius

ASME Y14.5M-1994 Standard makes no mention of a "full radius"

Hope this is the right place to ask this question - I am new to this.

A recent dispute with a cusotmer over a feature regarding a radius has prompted this post. The Feature is called out on the print as "R", the customer insists this means "Full Radius". I have looked through ANSI and do not see where it is specifically difined as such. Any input would be appreciated.
Thnx

I have never seen this before. The "R" represents a Radius, and usually on the print it will call out the size or full

to be more specific - The radius in question is at the bottom of a groove which as machined is .050 wide. The assesment of our engineering was that this groove had a .02 radius at the bottom of the groove leaving a .01 flat. The customer insists that the feature "R" indicated it should be a "Full Radius".

to be more specific - The radius in question is at the bottom of a groove which as machined is .050 wide. The assesment of our engineering was that this groove had a .02 radius at the bottom of the groove leaving a .01 flat. The customer insists that the feature "R" indicated it should be a "Full Radius".


Without seeing the drawing, if the "R" had a leader pointing to the center of the bottom of the groove, and no associated size callout, it would have to be assumed that full radius was intended--a .025 radius in this instance. Use of just the "R" with no associated size callout is generally intended to mean "full radius."

A word about Y14.5M: Unless it's called out on the drawing, or otherwise contractually agreed to, it has no standing.

to be more specific - The radius in question is at the bottom of a groove which as machined is .050 wide. The assesment of our engineering was that this groove had a .02 radius at the bottom of the groove leaving a .01 flat. The customer insists that the feature "R" indicated it should be a "Full Radius".

This tells me the customer wants the bottom of the groove radiused - meaning a full radius. (0.025 Rad)

How did your engineers arrive at their conclusion??:confused:

James

Hope this is the right place to ask this question - I am new to this.

A recent dispute with a cusotmer over a feature regarding a radius has prompted this post. The Feature is called out on the print as "R", the customer insists this means "Full Radius". I have looked through ANSI and do not see where it is specifically difined as such. Any input would be appreciated.
Thnx

I guess I would take that as a radius groove too depending on how the "R" is designated. If it is just pointing to the bottom of the groove then yes I would agree it is a radius groove. If it points to both sides of the bottom of the groove it would mean a radius at each corner.

Just my 2 cents worth!:notme:

Friends,

We're debating an issue here and we have not seen the actual drawing.
Halfhog, is it possible to scan and attach the actual drawing to a post?

OK, ASME Y14.5M-1994 provides a definition of "Radius" and "Controlled Radius." I agree with Jim that unless this standard is actually referenced on the drawing, we (and the customer) have no legs to stand on. The most important question that is regrettably not being asked during contract review is: "What standard applies when interpreting this drawing?" Drawings are accepted at face value, only to find ourselves in big trouble when the preverbial "Doo-Doo" hits the fan.....

What do my Fellow Covers think?

Stijloor.

The radius was arrived at by looking at the model. However the engineering drawing was to take precedense.
Thank all of you for you're input. While this matter has been resolved I was quite curious as to others opinions, which is what brought me to this site.

Friends,

We're debating an issue here and we have not seen the actual drawing.
Halfhog, is it possible to scan and attach the actual drawing to a post?

OK, ASME Y14.5M-1994 provides a definition of "Radius" and "Controlled Radius." I agree with Jim that unless this standard is actually referenced on the drawing, we (and the customer) have no legs to stand on. The most important question that is regrettably not being asked during contract review is: "What standard applies when interpreting this drawing?" Drawings are accepted at face value, only to find ourselves in big trouble when the preverbial "Doo-Doo" hits the fan.....

What do my Fellow Covers think?

Stijloor.

I think it's a good idea to sort out ambiguities in the contract review stage, but when a drawing, evaluated at face value, uses no ambiguous dimensioning, there's often no good reason to question it whether a standard is called out or not. In the present instance, if (as I said in my initial response) There is an "R" with no associated size specification, and a leader that points to the center of the bottom of the groove, it would not cause anyone who knows what he's doing to wonder what was intended. The fact that the OP's engineers apparently made some sort of judgment call means that (A) the dimensioning might have been ambiguous somehow and (B) the customer should have been asked what was intended.

The radius was arrived at by looking at the model. However the engineering drawing was to take precedense.
Thank all of you for you're input. While this matter has been resolved I was quite curious as to others opinions, which is what brought me to this site.

Do you mean that the model and the drawing contradicted one another? If so, the customer should have been asked to clear things up, no?

I think it's a good idea to sort out ambiguities in the contract review stage, but when a drawing, evaluated at face value, uses no ambiguous dimensioning, there's often no good reason to question it whether a standard is called out or not.

Jim,

Not necessarily. It's possible to look at two identical drawings and still be subject to different interpretations. GD&T callouts is a good example. The symbols for concentricity and symmetry are the same for ASME and ISO subscribing companies, yet the inpretation and method of verification is entirely different.

Stijloor.

My experience in machining high tech, tight tolerance components for aerospace, sensors, and medical devices was that EVERY radius callout meant that the full profile of the feature was arced and not chamfered with a visible flat. We realize an arc in microscopic detail may be a series of small secants, but the overall impression should be of a smooth curve.

I'm curious - what tooling and setup gave the resultant profile with a flat at the bottom of the groove?

Jim,

Not necessarily. It's possible to look at two identical drawings and still be subject to different interpretations. GD&T callouts is a good example. The symbols for concentricity and symmetry are the same for ASME and ISO subscribing companies, yet the inpretation and method of verification is entirely different.

Stijloor.

See the attachment--the ISO and Y14.5M-1994 symbols for concentricity and symmetry are the same. Also, you'll note that I said that ambiguities should be cleared up in the beginning. This means that if you're not sure what's being specified, for any reason, you should ask the customer.

My point was that there are lots of reasons to ask questions, but it's not necessary in many cases.

In this particular case there is a mating part. The drawing with the questionable radius callout also had (ref) dimensions that further made the "R" callout suspect as to being a full radius. Eng laid the 2 models over each other and determined that a full radius would interfere. That determination as well as a supplied tool list that had an .05 cutter with a .02 radius on it was the basis for the decision to go with a .02 radius on the cutter as opposed to a full radius. However the tool list was not made part of the engineering.

If the designation is simply 'R', the actual surface simply needs to fall completely within the minimum and maximum envelopes of form for the radius size and tolerance as given on the drawing. If the designation is 'CR' or Controlled Radius, the radius must not only fall within the envelopes, but also can have no reverses.

Regards -John