Profile tolerance is the amount of deviation of a profile of a line or a surface. No surface can be made absolutely perfect. Due to machine or measurement variations, engineers should allow a deviation in the line elements or surfaces called profile tolerance.
What does a profile tolerance mean?
Profile tolerance is the amount of deviation of a profile of a line or a surface. No surface can be made absolutely perfect. Due to machine or measurement variations, engineers should allow a deviation in the line elements or surfaces called profile tolerance. Please make a note that, Profile tolerance can be used with or without a datum.
What are the advantages of tolerance?
What are the benefits of tolerance? Being able to accept one another’s differences can have positive effect on one’s well being. Being tolerant removes one’s self-imposed barriers and allows one to think more broadly and enjoy greater inner peace. Tolerance leads to less stress and greater happiness in the overall community.
How to promote tolerance?
- Commit yourself to nonviolence. ...
- Extend some help when you see someone upset, lost or puzzled.
- Teach a child how to be kind and calm. ...
- When you see any form of injustices and discrimination, speak out. ...
- When your anger is triggered, count to ten before you say anything. ...
- Try to be more compassionate and be more understanding of other people’s feeling.
What are the types of tolerance ranges?
Types of Tolerances
- Unilateral Tolerances. When the two limit dimensions are only above the nominal size as shown in the figure or only below the nominal size then the tolerance is said to ...
- Bilateral Tolerances. When the two limit dimension is above and below the nominal size, Then the tolerances are said to be bilateral.
- Compound Tolerances. ...
How do you do a profile tolerance?
0:011:27GD&T Profile of a Surface (Basics) - YouTubeYouTubeStart of suggested clipEnd of suggested clipYou could take your cad model and then create a version of it . 03 millimeters smaller and . 03MoreYou could take your cad model and then create a version of it . 03 millimeters smaller and . 03 millimeters larger. And those would be the boundaries of your tolerance.
Is profile tolerance Plus or minus?
Size of the opening is given by the basic dimensions, but size tolerance is provided by the Profile of a Surface constraint. Form is also controlled by this tolerance, as each point must be within the tolerance zone, which is plus or minus 0.0025” from the basic dimension.
How many type of profile tolerances are there?
There are two types of profile tolerances.
Does profile tolerance control position?
When used with datums, profile can mimic all the orientation symbols (perpendicularity, parallelism, angularity) and even control the location and size of a feature or surface. All of these tolerance symbols specify how much a surface of any geometric shape can vary from its true form.
How is profile tolerance measured?
When measuring the profile tolerance of a plane, you are checking whether a designed part's curved surface is made to the specified design. Unlike the profile tolerance of a line, the measurement of the profile tolerance of a plane involves the entire specified curvature.
Is profile tolerance bilateral?
Bilateral profile tolerance means variation from the true profile is permitted in equally in both directions. Unequally disposed profile tolerance means that more variation from the true profile is permitted in one direction than the other.
What are the 3 types of tolerance?
A tolerance is an acceptable amount of dimensional variation that will still allow an object to function correctly. Three basic tolerances that occur most often on working drawings are: limit dimensions, unilateral, and bilateral tolerances.
Does profile tolerance need a datum?
It requires specifying in a note on a drawing or in some other document that basic dimensions are to be derived from the CAD model. Once again we have a profile tolerance without a datum reference. The tolerance points to a surface, and it has a circle at the knee of the arrow.
How do you choose tolerance?
How to Choose Tolerances: A Step-by-Step GuideStep 1: Identify the tolerances that matter. ... Step 2: Perform a cost-benefit analysis. ... Step 3: Consider your materials. ... Step 4: Consider your manufacturing tools. ... Step 5: Consider the manufacturing process. ... Step 6: Account for tolerance slack. ... Step 7: Put it all together.
What is the tolerance zone for profile of a line?
Profile of a Line Tolerance Zone The tolerance zone is made of two parallel lines that follow the true profile in either direction. Unless stated otherwise, these parallel lines are assumed to be equidistant from the true profile. The distance between the two parallel curves is the tolerance limit.
What does profile of a line mean?
Profile of a line describes a tolerance zone around any line in any feature, usually of a curved shape. Profile of a line is a 2-Dimensional tolerance range that can be applied to any linear tolerance.
What is the difference between flatness and profile?
1:187:03GD&T: Profile vs Flatness - YouTubeYouTubeStart of suggested clipEnd of suggested clipMust lie so there's no relation to individual features the definition for profile is that there's aMoreMust lie so there's no relation to individual features the definition for profile is that there's a tolerance zone that extends perpendicular to the basic surface or just the surface of the part.
What is a plus minus tolerance called?
Plus/Minus Tolerancing, also called Limit Tolerancing, is a two dimensional tolerancing system that is probably the most familiar way of expressing tolerances there is.
What is profile of a line in GD&T?
The profile of the line requirement indicates whether the curvature of a designed part is made to its design. The value indicates any distortion in the profile line (line element that appears on the cross-section of a surface).
How do you read position tolerance?
An example of position tolerance is shown below. The top figure shows the position symbol applied to two holes. The boxed symbols can be read "relative to datums A, B, and C, the position of these hole centers shall lie within a cylindrical tolerance zone of diameter 0.3".
Does profile tolerance require datum?
Profile can control, form, location, orientation, and size or any subset of these. Profile can be used with or without datum references and with or without basic dimensions.
What is profile tolerance?
A Profile is the outline of an object in a given plane. Profile tolerance also defines a uniform boundary around a surface within where the elements of the surface must lie. Profile is a three-dimensional tolerance that applies in all directions regardless of the drawing view where the tolerance is specified.
What is a surface profile?
Profile of a surface is a three-dimensional tolerance. Surface profile tolerance limits the amount of error a surface can have relative to its true profile. Common applications for profile of a surface include controlling the size, location, orientation and/or form (or any combination of the aforementioned) of a planar, curved, or irregular surfaces, like polygons, cylinders, surfaces of revolution, or cones, and coplanar surfaces. Datums are normally used, but are not required, if datums are not referenced, the tolerance only limits the form of the profile; if three datums are referenced, the tolerance limits the form, location, and orientation. Tolerance zone is bilateral unless otherwise specified. it can be specified between two points or all-around using the same method for profile of a line between two points. Profile callout (feature control frame) is applied to a true profile on the drawing. The true profile is related to the datums reference with basic dimensions. Surface profile all around used for surfaces that have a constant, uniform cross-section shown on drawing by using the ‘ALL AROUND’ symbol on the leader connecting the feature control frame to the profile. Result is a tolerance zone consisting of two parallel boundaries equal in width to the tolerance. The tolerance zone should be perpendicular to a datum plane.
Why use profile tolerancing?
Profile tolerancing provides benefits for both the supplier and the device manufacturer in terms of product design and inspection. There are several advantages for medical device designers who use position and profile tolerancing instead of linear dimensioning. When design intent is conveyed unambiguously, OEMs don't have to field multiple questions from suppliers as they design and build a process for manufacturing and inspection. Using profile tolerancing tools like SmartProfile software enables parts to be inspected in a shorter time while minimizing measurement error compared with conventional methods. For example, looking at an application on a complex feature for an implantable medical device, inspection using linear dimensioning methods would typically take more than 60 minutes per part. Implementing profile dimensioning methods with this same feature requires less than 10 minutes for inspection, with improved accuracy. Such time savings, if multiplied over an entire production run, would increase throughput and help to alleviate potential bottlenecks during in-process and finished-goods inspections.
How many linear dimensions can be replaced by a single profile tolerance requirement?
In some applications, a single profile tolerance requirement can replace up to 20 linear dimensions, thereby reducing inspection time from hours to minutes.
What is profile analysis software?
The CAD features are selected for dimensioning, linear, size, or GD&T, and the tolerances are entered. The program is saved and can be used again, eliminating the need for recreating the program. At this stage, the measured points are imported, a quick alignment is done, and the points are evaluated. The profile analysis software performs an optimum fit analysis of the measured points to the CAD model. The measured points are translated and rotated until the optimum fit is achieved.
What is GD&T tolerance?
The GD&T standard defines these particular features (two sets of parallel planes) as dimensioned and toleranced as two independent features of size. When only a tolerance of size is specified, it does not control the orientation or location relationship between individual features. Figure 3 shows that an individual feature of size can fit within its allowable tolerance of ±0.1 mm, but can also fall outside the perceived outer boundary in the opposing direction.
What are the challenges of precision manufacturing?
One of the challenges facing precision manufacturers and their medical device manufacturing partners is the increasing feature complexity of tight-tolerance parts. These complex geometries can result in long inspection and verification times and put even the most sophisticated measurement equipment and processes to the test. In addition, design, manufacturing, and quality engineers are often frustrated by communication errors over these features.
Is profile tolerancing an OEM?
An OEM that is poised to embrace profile tolerancing will no doubt run into resistance from those who would prefer the way things have always been done. It is not just internal naysayers, but also suppliers that might fight the change. In addition, the investment for an OEM's suppliers can be steep in terms of training, equipment, and software.
What is a 3 dimension tolerance zone?
3-Dimensional tolerance zone existing of 2 parallel surface curves that follow the contour of the surface profile across the entire length of the surface. This tolerance zone may or may not be referenced by a datum.
What is a profile on a surface?
Profile of a surface describes a 3-Dimensional tolerance zone around a surface, usually which is an advanced curve or shape. If it is called out on a curved surface, like a fillet on a welded part, the entire surface where the radius is has to fall within the tolerance zone. Profile controls all the points along the surface within a tolerance range that directly mimics the designed profile. Any point on the surface would not be able to vary inside or outside by more than the surface profile tolerance. Usually, when surface profile is required, there are no tolerances on the dimensions that describe the surface and use the GD&T callout to give the acceptable range.
What is a datumless profile control?
A profile control without any datums attached to it is a form control. This means that the profile tolerance has to be tighter than the size tolerance due to Rule #1 and serves to refine the surface. Think of a datumless profile control as restricting the smoothness of the face/surface.
What is profile in datums?
When used with datums, profile can mimic all the orientation symbols (perpendicularity, parallelism, angularity) and even control the location and size of a feature or surface. All of these tolerance symbols specify how much a surface of any geometric shape can vary from its true form.
Is line tolerance tighter than surface tolerance?
Sometimes profile of a line is used in conjunction with profile of a surface. In these cases, the line profile tolerance will be tighter than the surface tolerance. This ensures that along any specific cross-section of the profile, the part will be tightly controlled, while at a looser extent, the total profile is also controlled.
Using a Profile Measurement System
Put the stylus on the measuring starting point of the target and specify the measurement length to measure. The system performs analysis using the measured data and the theoretically correct data registered in the system, and outputs the P/V value (the maximum and minimum values, as well as the standard deviation σ from the theoretically correct feature)..
Using a Coordinate Measuring Machine (CMM)
The stylus position can be changed to measure the target at any angle or in any location. As the stylus only comes into light contact with the measurement point, there is no concern of deformation on the measurement surface caused by the load (measuring pressure) of the stylus. Additionally, this enables quick, stable measurement with high accuracy..
What is profile tolerance?
The profile tolerances of lines and planes are also used in specifying location tolerance. Specifications are indicated in the feature control frame the same way for form tolerance and location tolerance. Profile Tolerance of Line. Profile Tolerance of Plane.
What does profile of line requirement mean?
The profile of the line requirement indicates whether the curvature of a designed part is made to its design . The value indicates any distortion in the profile line (line element that appears on the cross-section of a surface). The cross-section line cutting across the specified curvature must be within the tolerance zone.
What is the diameter of a target profile on a cross section parallel to the projection plane?
The target profile on any cross-section parallel to the projection plane must be between the two envelopes created by a circle with a diameter of 0.03 mm and a center on the line having a theoretically exact profile.
What does the circle U mean in a tolerance?
Take note that either depicting an alternative tolerance disposition on the part (with dimensions) or making use of the unequally disposed profile symbol (circle U) changes how the tolerance is applied. The tolerance value after the circle U indicates the amount of tolerance given in the direction that adds material (makes the part heavier) to the part.
How is profile measured?
Profile of a line is measured using a gauge that is referenced to the true profile at the given specific cross-section. Because there are an infinite amount of 2D cross-sections of any part, the number or locations of measurement points can be specified on the drawing. Profile is usually measured using a CMM for more complex geometries.
What is a profile of a line?
Profile of a line describes a tolerance zone around any line in any feature, usually of a curved shape . Profile of a line is a 2-Dimensional tolerance range that can be applied to any linear tolerance. If it is called out on a surface, like a radius on a part – profile of a line would specify how much that cross-section could vary from a true curved radius. Profile of a line takes a cross section at any point along the surface and sets a tolerance zone on either side of the profile. The profile of a line callout can also be set with an all-around leader or given a specific range (see example).
What is a 2 dimension tolerance zone?
2-Dimensional tolerance zone existing of two parallel curves that follow the contour of the true surface profile. The application on where the tolerance zone applies can be specified on the drawing. This tolerance zone may or may not be referenced by a datum.
How many replies are there on the profile of a line?
35 replies on “Profile of a Line”
Does line tolerance control the specific dimension?
Note: The profile of a line tolerance does not control the specific dimension that every surface point is located – that is done by the dimensions of the part. It only controls how tightly the points fall into a “true” curve, similar to the circularity tolerance.
Is profile of a line related to profile of a surface?
Profile of a line is of course closely related to profile of a surface. The difference being that profile of a line takes only the measurement at a specific cross-section and does not take into account the variance of one cross-section to the next.
What is profile tolerance?
If we have a basic dimension to the surface instead of a coordinate dimension, then the profile tolerance controls the location as well as the orientation and form.
What does the double circle mean on a profile tolerance?
The profile tolerance in the figure below has a double circle at the knee of the arrow. The double circle is the "all over" symbol. This means that the profile tolerance applies all over the entire part in all directions.
How does a 0.2 tolerance work?
We can see below how the composite tolerance works. The 0.5 tolerance zone is stationary relative to datums [A] and [B]. The 0.2 tolerance zone is free to move within the 0.5 tolerance zone. The 0.2 zone can move up and down and side to side within the 0.5 tolerance zone. So the 0.2 tolerance zone does not refine the movement up/down or side to side. However, the 0.2 zone is constantly parallel to datum [A]. Therefore the 0.2 tolerance zone refines the amount that the label is able to rotate (the orientation) relative to datum [A].
How does the bottom line of a composite tolerance work?
So it will control the orientation in the left view by holding each cross section between parallel lines that are oriented but not located to datum A. The tolerance zone for the bottom line will float within the tolerance zone for the top line.
What is the tolerance zone of parallelism?
Within this tolerance zone, the parallelism defines a 0.1 wide tolerance zone that floats within the 0.3 wide tolerance zone. The 0.1 wide tolerance zone controls the form and orientation of the wall.
What are the two flavors of profile?
Profile comes in two flavors - profile of a surface and profile of a line.
When to use flatness profile?
Flatness can only be applied to one surface at a time unless the Continuous Feature symbol is used to indicate that the two surfaces must be considered to be one surface.
