1.1 Current Exam Facts

ASME GDTP Senior Level Exam

Track your progress as you read

Finished sections get a check mark.

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

1.1 Current Exam Facts

Key Takeaways Explain This Topic AI

ASME GDTP Senior (Y14.5-2009) is a 150-question, 6-hour, closed-book, multiple-choice exam delivered at Prometric centers.

Passing requires at least 78% overall AND at least 50% in EACH of the seven weighted content categories — a strong overall score cannot rescue a failing category.

Datum Referencing (30%), Location (25%), and Profile (20%) together drive 75% of the exam, so they deserve the bulk of study time.

Eligibility requires a minimum of 3 years of relevant GD&T professional experience, personally performed within the last 3 years and demonstrating independent application; Technologist certification is NOT a prerequisite and ASME membership is NOT required.

The application/exam package costs $623 (retest $413); certificates are valid 3 years and recertification costs $125 via ASME PC-Connect with at least 24 months of verified GD&T involvement.

Last updated: August 2026

ASME GDTP Senior Level — Current Exam Facts (Y14.5-2009)

Quick Answer: The ASME GDTP Senior Level exam based on ASME Y14.5-2009 is a 150-question, 6-hour, closed-book, multiple-choice exam administered at Prometric centers. It costs $623 (retest $413) and requires a 78% overall score with at least 50% in each of seven weighted content categories. Candidates must document a minimum of 3 years of relevant GD&T professional experience.

The ASME Geometric Dimensioning and Tolerancing Professional (GDTP) Senior Level certification, based on ASME Y14.5-2009, is the senior of ASME's two GDTP tiers. ASME positions Senior as the design-authority credential: the person who selects geometric controls and applies GD&T to drawings, tooling, and verification. It is distinct from the Technologist tier, which measures interpretation. This guide tracks the Y14.5-2009 Senior exam to match the official practice bank.

Exam Format and Delivery

• Item Y14.5-2009 Senior
• Questions 150 multiple-choice
• Time limit 6 hours maximum
• Format Closed book — no reference materials, including the Y14.5 standard
• Delivery Prometric testing centers
• Application/exam package fee $623
• Retest fee $413
• Scheduling window 180 days from application approval; one-time 180-day extension available for a fee
• Results Emailed within 24-48 hours; no grades released by phone

You take the exam on a Prometric workstation. ASME publishes one hard rule about materials: the examination is closed book , so notes and copies of Y14.5 are out. ASME does not publish a calculator or scratch-paper policy; candidates who have sat the exam consistently report that the test center supplies writing materials and permits a simple non-programmable calculator , which is the normal Prometric convention. Treat that as likely but unconfirmed — read the personal-items and calculator rules in your own Prometric confirmation before test day, and prepare as though you must do every calculation by hand. The 6-hour clock is long, but the question bank rewards steady discipline — budget about 2.4 minutes per question and protect the last 30 minutes for review. A practical exam-day tactic is to answer the high-weight categories (Datum, Location, Profile) first while you are fresh, then sweep the small categories, and finish with flagged calculation questions rather than burning minutes early on a single hard stack.

Passing Score: 78% Overall + 50% per Category

To pass Y14.5-2009 Senior you must achieve at least 78% overall AND at least 50% in EACH of the seven content categories . A high overall score cannot rescue a failing category: a candidate who scores 90% overall but 48% in, say, Runout, fails the exam. Conversely, a candidate who scores exactly 78% overall with every category at or above 50% passes. This rule is why the blueprint weights below drive every study plan in this guide — you cannot ignore a small category, because 50% is still a hard floor.

Worked Example

Imagine two candidates:

Candidate A: 92% overall, 49% in Runout, every other category above 70%. Result: Fail — Runout is below 50%.

Candidate B: 79% overall, 51% in every category. Result: Pass — clears both the 78% overall floor and the 50% per-category floor.

Candidate A's 92% is irrelevant. The per-category floor is absolute, not averaged.

The Seven Content Categories and Weights

• # Category Weight Approx. questions (of 150)
• 1 Scope, General Dimensioning, and Symbology 10% 15
• 2 Datum Reference Frames (Datum Referencing) 30% 45
• 3 Form 5% 8
• 4 Orientation 5% 8
• 5 Location 25% 37
• 6 Profile 20% 30
• 7 Runout 5% 8

ASME's 2026 handbook labels these categories Scope, General Dimensioning, and Symbology and Datum Reference Frames ; the program page uses the shorter Dimensioning and Symbology and Datum Referencing . Same content, two labels. Datum Referencing (30%) and Location (25%) together drive more than half the exam. Profile (20%) is the third heavyweight. Treat these three as the spine of your preparation. The four small categories (Dimensioning & Symbology, Form, Orientation, Runout) still matter — the 50% floor applies to each — but they will not make or break your score the way the big three will.

Eligibility and Experience

Experience required: a minimum of 3 years of relevant GD&T professional experience. ASME's 2026 Applicant Information Handbook specifies that the description must cover work personally performed by the applicant within the last 3 years and must demonstrate independent application of GD&T principles. (Legacy "five years" copy still appears in places on ASME's program page; the 2026 handbook is the current applicant-facing document and is what ASME directs applicants to. If your application predates the change, confirm with ASME Customer Care.)

Technologist certification is NOT a prerequisite. You may sit Senior directly if you meet the experience requirement.

ASME membership is NOT required. The fees above are the same for members and non-members.

The experience log is the most common application stumbling block. Record employer, dates, role, and the GD&T tasks performed (selection, application, verification, gaging). Vague entries such as "used GD&T at work" are the kind of documentation ASME rejects.

Results, Validity, and Recertification

Results: Emailed within 24-48 hours of the exam, including the percentage correct within each part. ASME does not release scores by phone. A request to have failing results reviewed must be submitted in writing within 30 days of the notification date.

Certificate validity: 3 years from issuance.

Recertification: $125 via ASME PC-Connect, requiring verification of at least 24 months of GD&T involvement during the validity period. No retest is required if the recertification requirements are met.

Expiry notice: ASME notifies certificate holders at least six months before the expiration date on the certificate. Do not represent yourself as GDTP-certified once the 3-year validity lapses; renew through PC-Connect before expiry.

A Note on Revisions

ASME sells both a Y14.5-2009 Senior exam and a Y14.5-2018 Senior exam (150 Q, 6 hr, 74% overall + 50% per section, $495, retest $325), and states that certification is currently based on either the 2009 or the 2018 revision. The Y14.5M-1994 Senior exam remains available on request (150 Q, 6 hr, 80% overall, retest $413). This guide teaches the Y14.5-2009 Senior blueprint, which matches the official practice bank, and Section 1.4 maps the 2018 exam and its deltas. Passing one revision does not certify you in another — see Section 1.2 for the full comparison.