12.1 All-Around, All-Over, and Limited Scope

ASME GDTP Senior Level Exam

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1 Introduction & Exam Overview

1.1 Current Exam Facts 1.2 Senior Level vs Technologist and Y14.5 Revisions 1.3 How to Use This Guide and Study Strategy 1.4 The Y14.5-2018 Senior Exam and What Changed from 2009

2 Dimensioning and Symbology

2.1 Y14.5 Dimensioning Rules, Limits, and Fits 2.2 Basic Dimensions and Their Role 2.3 Feature Control Frame Structure and Reading 2.4 GD&T Symbols, Modifiers, and Communication 2.5 Screw Threads, Gears, and Splines 2.6 Angular Surfaces, Tapers, Radii, and Special Tolerance Cases

3 Datum Referencing I: Selection and Precedence

3.1 Functional Datum Feature Selection 3.2 Datum Precedence and Degrees of Freedom 3.3 Datum Targets 3.4 Datum Feature Simulators

4 Datum Referencing II: Modifiers and Shift

4.1 Multiple Datum Features and Datum Reference Frames 4.2 RMB, MMB, and LMB on Datum Features 4.3 Datum Shift Behavior 4.4 Planar vs Datum Feature of Size

5 Datum Referencing III: Setup and Calculations

5.1 Inclined and Translated Datum Features 5.2 Inspection Setup and Datum Establishment 5.3 Datum Calculation Walkthrough 5.4 Customized Datum Reference Frames and Rotational Constraint 5.5 Free State, Restrained Condition, and Nonrigid Parts

6 Form Controls

6.1 Flatness and Straightness 6.2 Circularity and Cylindricity 6.3 Rule #1, Form, and Size

7 Orientation Controls

7.1 Parallelism, Perpendicularity, and Angularity 7.2 Orientation Zones and Material Modifiers 7.3 Avoiding Unnecessary Orientation and Over-Control

8 Location I: Position and Boundaries

8.1 Position Tolerancing and True Position 8.2 Virtual and Resultant Condition 8.3 Bonus Tolerance at MMC and LMC

9 Location II: Application and Modifiers

9.1 Selecting MMC, LMC, and RFS by Function 9.2 Fixed and Floating Fastener Formulas 9.3 Projected Tolerance Zones 9.4 Coordinate Conversion and Appendix B Position Calculations

10 Location III: Patterns and Allocation

10.1 Composite Position Tolerancing 10.2 Patterns, Simultaneous Requirements, and Multiple Segments 10.3 Slots, Tabs, and Tolerance Allocation 10.4 Coaxial Feature Controls, Concentricity, and Symmetry

11 Profile I: Fundamentals and Strategy

11.1 Profile of Line and Surface 11.2 Defining the True Profile 11.3 Datum-Referenced Profile Strategy 11.4 Equal and Unequal Disposition

12 Profile II: Scope and Verification

12.1 All-Around, All-Over, and Limited Scope 12.2 Composite Profile and Coplanarity 12.3 Castings, Weldments, Sheet Metal, and CMM Evaluation 12.4 Combined Controls and Profile as a Refinement

13 Runout Controls

13.1 Circular and Total Runout 13.2 Datum-Axis Simulation and Rotating Parts 13.3 Runout vs Position, Profile, and Form

14 Exam Strategy and Calculations

14.1 Virtual/Resultant Condition and Bonus Formulas 14.2 Datum Shift and Worst-Case Boundary Calculations 14.3 Functional Gaging and Verification 14.4 Test-Day Tactics, Common Traps, and Review

12.1 All-Around, All-Over, and Limited Scope

Key Takeaways Explain This Topic AI

The all-around symbol (single circle on the leader) applies profile around the entire perimeter shown in a single view; it does not make a 2-D tolerance control a 3-D surface.

The all-over symbol (two concentric circles, the extent symbol) applies profile to the entire 3-D surface, every face and region, and is the most expensive scope to verify.

A chain line (phantom line) plus a length dimension, or a 'BETWEEN A AND B' note, limits a profile tolerance to a portion of a surface or to the region between two designated points.

Profile of a line with all-around controls each line element in the shown view only; surfaces outside that view are not controlled by that FCF.

The most expensive scope mistake is applying all-around (single circle) to a 3-D casting face when all-over (two circles) was intended; most of the surface is left unconstrained.

Last updated: August 2026

12.1 All-Around, All-Over, and Limited Scope

Profile tolerances can apply to a single line element, an entire perimeter in a view, an entire 3-D surface, or only a portion of a surface. ASME Y14.5-2009 distinguishes these cases by the symbols placed on the leader and the auxiliary notes that bound the extent of the zone. The Senior technologist must know exactly which symbol conveys which scope because the wrong symbol expands or shrinks the tolerance zone by orders of magnitude.

All-Around Symbol

The all-around symbol is a small circle placed at the junction of the leader line and the geometry in the view where the profile is shown. It tells the inspector that the profile tolerance applies to the entire perimeter of the feature in that single view — that is, around the complete cross-sectional outline displayed, end-to-end with no interruption. The zone is still a 2-D profile zone: for profile of a line, each cross-sectional element drawn in the view must lie within two equally-disposed (or unequally disposed) boundary curves offset from the true profile. The all-around symbol does NOT make a 2-D tolerance control a 3-D volume. It simply makes the perimeter in that one view fully covered with no interruption.

For a flat part with a complex outline shown in plan view, profile of a line with all-around is a clean way to control the entire outline with one callout. For a revolved part with a profile shown in section view, all-around drives every line element at every angular position because each line element repeats the same perimeter. Be careful: if the profile feature has multiple separate views showing different elements, each view needs its own all-around symbol, or the scope covers only the view where the circle appears.

All-Over Symbol

The all-over symbol (sometimes called the extent symbol) is two concentric circles placed at the same junction. It tells the inspector that the profile tolerance applies to the entire 3-D surface — every face, every fillet, every region — of the controlled feature, not just the perimeter shown in one view. All-over is used with profile of a surface when a part's whole skin must be controlled. Because all-over sweeps the entire surface, it is the most expensive scope to verify; the inspector cannot sample only the perimeter and declare conformance.

A frequent Senior-level trap: applying the all-around symbol (single circle) to a surface that is genuinely 3-D, such as a complex casting face, when the intent was all-over (two circles). The single-circle all-around symbol only verifies the perimeter in one view; the rest of the surface is unconstrained. The reverse trap also occurs: specifying all-over when only the perimeter in one view matters adds unnecessary CMM time without design benefit.

Limited Scope: Chain Line and Between

When a profile tolerance is intended to cover only a portion of a surface, Y14.5-2009 limits the scope with a chain line (drawn as a phantom line) placed adjacent to the controlled region, plus a length dimension or reference letters. The chain line physically marks the extent on the drawing; a dimension defines its length; or the FCF carries a "BETWEEN A AND B" note that ties the extent to two designated points marked on the true profile. Outside the marked extent, the surface has no profile control from that FCF (though other controls may apply).

Between-Points Extent

The between-points extent is a specific limited-scope case. The FCF carries the note BETWEEN A AND B , and the drawing marks the two points A and B on the true profile. The profile zone applies only to the portion of the surface lying between those two points. This is useful when a surface has a critical transition region — for example, the blend between a cylinder and a cone — and the designer wants to tighten only that region.

Scope-Decision Table

• Condition Symbol/Note Scope of zone
• Single line element, one view, no symbol None One element
• Entire perimeter in one view All-around (single circle) Perimeter of that view
• Entire 3-D surface All-over (two concentric circles) Full surface, every face
• Portion of surface Chain line + length / between A and B Only the marked extent
• Between two points "BETWEEN A AND B" in FCF Region between the two points
• Worked Scope Decision

A sheet-metal bracket has a 0.8 mm profile of a surface control on the outer flange. The drawing shows the bracket in one side view with the leader pointing at the upper flange face only. If the designer places a single circle (all-around) on that leader, the inspector verifies the upper-flange perimeter as seen in the side view only — not the underside, not the return flange. If the designer intended the entire outer skin of the bracket, the callout must use all-over (two circles) AND must clearly call out profile of a surface, not profile of a line. A field change that swaps one symbol for the other changes the verification program and the part's acceptability.

Common Traps Summary

The Senior exam frequently tests three scope mistakes. (1) Using all-around (single circle) where all-over (two circles) was intended — this leaves most of the surface unconstrained and is the most expensive misinterpretation because the part can pass while grossly out of spec on the unverified faces. (2) Reading profile of a line with all-around as if it controlled a 3-D surface — it does not; profile of a line applies line element by line element, and all-around only extends each element to the full perimeter in the view. (3) Forgetting that a limited-scope chain line or between A and B note restricts the zone; without the note the profile applies to the entire feature as drawn, and the inspector may reject good parts by measuring outside the intended extent.