The Machinist Red Seal exam (General Machinist, 429A, in Ontario) has 135 multiple-choice questions, a four-hour writing time and a 70 per cent pass mark, which means 95 correct answers. The questions come from eight blocks, which the occupational standard calls major work activities. Conventional lathes and conventional milling machines carry 28 questions each (20.7 per cent each) and CNC machines 27 (20 per cent), so those three blocks are 83 of the 135. Common occupational skills has 13, benchwork 11, precision grinding machines 11, drill presses 9 and power saws 8. The Red Seal Program puts the mix at 50 to 60 per cent procedural and application, 25 to 35 per cent critical thinking and 10 to 20 per cent knowledge and recall. A two-page formula sheet and an acronym list are provided at the sitting. The sheet covers rpm, feed, machining time and thread formulas; it has no taper, sine bar or indexing formulas.
01What is the Machinist Red Seal exam?
It is the national certification exam for the trade that the Red Seal Program calls Machinist. Ontario calls the trade General Machinist, and 429A is Ontario's trade code for it. You will also see it called the interprovincial (IP) exam or, in Ontario, the certifying or C of Q exam. In Ontario these all name the same sitting: one interprovincial Red Seal exam, and passing it earns the Certificate of Qualification with the Red Seal endorsement.
The content is set nationally. According to the Red Seal Exam Preparation Guide, tradespeople from across Canada decide what goes into the trade's Red Seal Occupational Standard, write and review every exam question, and decide how many questions each section gets. The exam is then administered by the provincial and territorial apprenticeship and certification authorities; in Ontario that is Skilled Trades Ontario.
The format is the same as every Red Seal exam: multiple choice, four options (A to D), one correct answer, one mark per question and no penalty for a wrong answer. The Machinist exam has 135 questions and the writing time is four hours, about 1 minute 47 seconds per question. The pass mark is 70 per cent. Seventy per cent of 135 is 94.5, so you need 95 correct answers and can miss 40.
The standard behind the exam is the 2018 Red Seal Occupational Standard for Machinist (catalogue number Em15-3/16-2018E-PDF). The exam information page and the Self-Assessment Guide give the 135-question breakdown in its task numbering, and when we checked on October 3, 2026, the Red Seal site showed no new exam under development for this trade. The preparation guide stresses that the exam covers the trade across Canada at the journeyperson level, not only the work you do: a CNC machinist will still see benchwork, power saw and precision grinding questions, and a manual machinist will still see CNC programming.
02What is on the Machinist exam?
The Red Seal Program publishes how many questions come from each major work activity. For Machinist the 135 questions break down like this.
| Block | Major work activity | Questions | Share of exam |
|---|---|---|---|
| A | Performs common occupational skills | 13 | 9.6% |
| B | Performs benchwork | 11 | 8.1% |
| C | Machines using power saws | 8 | 5.9% |
| D | Machines using drill presses | 9 | 6.7% |
| E | Machines using conventional lathes | 28 | 20.7% |
| F | Machines using conventional milling machines | 28 | 20.7% |
| G | Machines using precision grinding machines | 11 | 8.1% |
| H | Machines using computer numerical control (CNC) machines | 27 | 20.0% |
| Total | 135 | 100% | |
Three blocks carry the exam. Block E, conventional lathes, and Block F, conventional milling machines, have 28 questions each (20.7 per cent), and Block H, CNC machines, has 27 (20 per cent). Together they are 83 of the 135 questions, 61.5 per cent. Block A follows at 13, then B and G at 11 each and D at 9. The lightest is C, power saws, at 8 (5.9 per cent). The shares here are worked out from the question counts and rounded to one decimal, so the column adds to 99.8. The Self-Assessment Guide rounds them to 9, 8, 6, 7, 21, 21, 8 and 20 per cent; the question counts are the figures to rely on.
03What does each block cover?
The task names below are the ones the 2018 standard lists under each major work activity, with the number of questions the Red Seal Program assigns to each. The standard has 20 tasks and 110 sub-tasks, and questions are written to the sub-tasks. Every one of the 20 tasks carries questions, communication and mentoring included, and the 2018 standard marks no sub-task as not common core. The largest single task is setting up conventional milling machines (F-14) with 15 questions, then setting up and operating conventional lathes (E-12 and E-13) with 14 each, operating conventional milling machines (F-15) with 13 and CNC programming (H-18) with 12.
Block A: Common occupational skills (13 questions)
Five tasks. Performs safety-related tasks (2 questions) covers maintaining a safe work environment and using PPE and safety equipment. Organizes work (3) covers interpreting documentation and planning the sequence of operations. Uses communication and mentoring techniques (2) is tested here, which is not the case in every trade. Processes workpiece material (4), the largest, covers selecting material, hoisting, lifting and rigging, marking workpieces for identification, heat treatment, quality control, deburring and sketching parts. Maintains machines, tooling and inspection equipment (2) covers cleaning and lubricating machines, sharpening tooling, cutting fluid and coolant, troubleshooting equipment, machine alignment and inspection equipment.
Free block A practice questions: Safety, Drawings & Materials →
Block B: Benchwork (11 questions)
Two tasks. Performs hand processes (8 questions) covers layout, sawing, filing, hole making, threading, installing thread inserts, broaching, pressing, forming and finishing. Under threading the standard asks you to calculate and select tap drill sizes in metric and imperial. Refurbishes components (3) covers disassembling, analyzing and assembling components.
Free block B practice questions: Benchwork & Hand Tools →
Block C: Power saws (8 questions)
Two tasks. Sets up power saws (5 questions) covers selecting the saw type and the blade, installing blades, selecting speeds and feeds, making adjustments and setting up the workpiece. The standard's list of power saws runs from vertical and horizontal saws to reciprocating or power hacksaws and cold circular, abrasive, cutoff, contour and friction saws. Operates power saws (3) covers straight and angle cuts and cutting irregular shapes.
Free block C practice questions: Band Saws & Power Saws →
Block D: Drill presses (9 questions)
Two tasks. Sets up drill presses (5 questions) covers selecting the drill press type (the standard lists sensitive, upright, radial arm and magnetic base), planning the operation, speeds and feeds, jigs, fixtures and work holding devices, and tooling. Operates drill presses (4) covers drilling holes, cutting countersinks, counterbores, chamfers and spot faces, tapping, and finishing holes.
Free block D practice questions: Drill Press & Tapping →
Block E: Conventional lathes (28 questions)
Two tasks of 14 questions each. Sets up conventional lathes covers selecting the lathe type, planning the operation, work holding devices, tooling, accessories such as taper attachments, steady rests and follower rests, setting up the workpiece, and selecting speeds and feeds. Operates conventional lathes has ten sub-tasks: facing, turning external surfaces, drilling, boring, reaming, turning tapers, knurling, cutting grooves, cutting threads and parting off. For tapers the standard lists four turning methods (taper attachment, tailstock offset, compound rest and form tool), the calculations required for tapers, and checking methods that include plug and ring gauges and the sine bar.
Free block E practice questions: Lathe, Tapers & Threading →
Block F: Conventional milling machines (28 questions)
Sets up conventional milling machines (15 questions) is the largest single task on the exam. It covers selecting the machine type (vertical, horizontal or universal, ram and turret, horizontal boring mill and jig borer are on the standard's list), planning the operation, work holding devices, tooling, accessories such as the dividing head and rotary table, setting up the workpiece, and speeds and feeds. Operates conventional milling machines (13) covers milling surfaces, profiles and pockets, slots, grooves and keyways, cutting gears and splines, and drilling, reaming, countersinking, counterboring, tapping and boring on the mill. Under gears and splines the standard has you calculate the indexing requirements from the number of teeth or splines to be cut.
Free block F practice questions: Milling, Indexing & Gears →
Block G: Precision grinding machines (11 questions)
Two tasks. Sets up precision grinding machines (6 questions) covers selecting the machine type, planning the operation, work holding devices, mounting the grinding wheel, accessories, setting up the workpiece, and speeds and feeds. Operates precision grinding machines (5) covers grinding flat surfaces on a surface grinder, grinding profiles, internal and external cylindrical and tapered surfaces, grinding tools and cutters, and finishing holes on a honing machine.
Free block G practice questions: Precision Grinding & Wheels →
Block H: CNC machines (27 questions)
Three tasks. Performs CNC programming (12 questions) covers process documentation, manual input programs, transferring programs to and from control memory, optimizing programs, creating 2D and 3D models and programming with computer-aided manufacturing (CAM). Sets up CNC machines (8) covers selecting and setting up tooling and tool holders, setting up workpieces, establishing the work datum and verifying the program. Operates CNC machines (7) covers adjusting offsets, monitoring machining processes, and interrupting and restarting the program cycle.
Free block H practice questions: CNC Programming & Set-Up →
04What kind of questions are they?
The Red Seal Program describes the Machinist question mix as knowledge and recall 10 to 20 per cent, procedural and application 50 to 60 per cent and critical thinking 25 to 35 per cent. On 135 questions that is roughly 14 to 27 recall questions, 68 to 81 procedural and 34 to 47 critical thinking. The critical thinking share is the fourth highest of the thirteen trades we cover, behind Automotive Service Technician (310S), Truck and Transport Mechanic (310T) and Heavy Duty Equipment Technician (421A).
The exam information page gives one example of each type. The recall example asks which product is used to check the final fit of mating tapers. The procedural example asks what process is used to achieve a spot face. The critical thinking example asks for the size of the gauge block build-up used with a 5 in. sine bar to check a workpiece with a taper of 3/4 in. per foot, which you have to calculate.
The Red Seal Exam Preparation Guide says procedural questions might include calculations and interpretations of diagrams, and that some critical thinking questions are complex and need an analysis of the situation and more than one calculation. In this trade that means method: choosing the work holding, setting a speed and feed from a chart value, planning the order of operations, setting up a taper, a thread or an indexing job, and reading a fault from its symptoms. There are no trick questions, but the incorrect options are not always obvious.
05What do you get in the exam room?
The Red Seal Exam Preparation Guide lists what you are provided with: an exam booklet, a diagram booklet if one is required, a pencil and eraser, a calculator if needed, and a bubble sheet to record your answers. It also lists other reference material "if required": an acronym list, math formulas and code book information. Scrap paper is provided too.
For Machinist the exam information page publishes both a formula sheet and an acronym list and says both will be provided with the exam sitting. The acronym list has 37 entries, among them BHC (bolt hole circle), CRC (cutter radius compensation), WCS (work coordinate system), HSS, SHCS and TiN, the thread series UNC, UNF, UNS and NPT, and units such as sfpm, ipm, m/min and mm/min. You get the meaning of each acronym; you still need to know what the thing does. The page lists no code book information for this trade.
The guide's rules say no materials, bags, phones, watches or personal calculators in the room, and your province or territory may have rules of its own; ask your provincial or territorial office about anything else. More on the day itself is in what to expect on exam day.
06What is on the Machinist formula sheet, and what is not?
The sheet is two pages. It gives one constant, π = 3.1416, four abbreviations (fpr for feed per revolution, fpt for feed per tooth, rpm and tpi) and fourteen formulas.
| Formula | As the sheet abbreviates it |
|---|---|
| Bend allowance (for a 90° bend) | (r + (0.4 × T)) × 1.5708 |
| Cutting force | L × T × S (length × thickness × shear strength) |
| External thread depth (imperial) | 0.6134 × P |
| Internal thread depth (imperial) | 0.5413 × P |
| Feed rate per minute | fpt × N × rpm |
| Measurement over wires | MD + (3 × WD) − (1.5155 ÷ tpi) |
| Measurement over wires | PD − (0.866025 × P) + (3 × WD) |
| Pitch diameter (metric) | MD − (0.6495 × P) |
| Revolutions per minute (imperial) | (12 × CS) ÷ (πD) |
| Revolutions per minute (metric) | (1 000 × CS) ÷ (πD) |
| Tap drill size | MD − P |
| Time (for lathe) | L ÷ (fpr × rpm) |
| Time (for mill) | L ÷ (fpt × N × rpm) |
| Wire size | 0.57735 × P |
That covers speeds, feeds, machining time, threads and one bend. It does not cover everything the exam can ask you to calculate. There is no taper formula on the sheet (taper per foot, the compound rest angle or the tailstock offset), no sine bar formula, no indexing formula for the dividing head, no gear formula and no trigonometry. Yet the standard lists taper calculations, sine bar values and indexing requirements among the things a machinist calculates, and the Red Seal Program's own critical thinking example is a sine bar build-up for a taper given in inches per foot. Learn those relationships until you can write them down from memory.
Two cautions about the formulas that are on the sheet. The rpm formulas are the full ones, with 12 or 1 000 on top and π times the diameter underneath, and the sheet's value of π is 3.1416. And the units are implied, not printed: the imperial rpm formula takes the cutting speed in surface feet per minute and the diameter in inches, the metric one takes metres per minute and millimetres, and the pitch of an inch thread is 1 divided by its threads per inch. Our free tap drill chart and calculator shows the major diameter minus pitch rule next to the percentage-of-thread formula.
07How much CNC is on the exam, and is it inch or metric?
CNC machines are Block H: 27 of the 135 questions, 20 per cent of the exam. Programming is the largest part at 12 questions, and its sub-tasks include both manual input programs and CAM; the standard's list of programming codes is G-codes, M-codes and coordinates. Set-up is 8 questions and operation 7. The other 108 questions are not CNC: 84 are on conventional machines (power saws, drill presses, lathes, milling machines and precision grinders), 11 on benchwork and 13 on common occupational skills. The standard's own trends section says conventional machining skills continue to form the basis of the trade and are a prerequisite to setting up and programming CNC machine tools safely and efficiently.
On units, prepare for both. The formula sheet has separate imperial and metric rpm formulas, imperial thread depth formulas and a metric pitch diameter formula. The acronym list carries in., ft., sfpm, ipm and tpi alongside mm, m/min and mm/min. The standard asks for tap drill sizes to be calculated in metric and imperial, and the official critical thinking example is in inches. The Red Seal Program does not publish what share of the questions use each system.
08How do you become a Red Seal machinist in Ontario?
In Ontario the trade is General Machinist (429A), and it is a non-compulsory trade. According to Skilled Trades Ontario, the Certificate of Qualification in this trade does not have to be renewed, and the trade is not on its Public Register.
Skilled Trades Ontario sets the apprenticeship at 8,000 hours, approximately four years: 7,280 on the job and 720 in school over three levels, with Grade 12 as the academic entry level in its 2025 trade report. Passing the certifying exam, the Red Seal exam, earns the Certificate of Qualification. Skilled Trades Ontario issued 81 General Machinist Certificates of Qualification in 2025. Experienced workers who did not complete an Ontario apprenticeship use its Trade Equivalency Assessment; see how to challenge the Red Seal exam.
The national standard recommends four levels of technical training and 7,200 total hours and notes that each jurisdiction implements this in its own way; Ontario's figures are the ones above. The standard also recognizes overlaps with tool and die makers, mould makers, welders and industrial mechanics (millwrights). Each of those is a separate trade, and the Machinist exam is its own exam; for the millwright exam see the 433A Millwright exam guide.
Elsewhere, each province and territory administers the exam and sets eligibility, fees and rewrite rules. See the Ontario Red Seal exam guide, Alberta, British Columbia, Saskatchewan, Manitoba or the guides by province, compare Red Seal exam fees by province, and read what happens if you fail the Red Seal exam before you book.
09How hard is the Machinist Red Seal exam?
It is demanding in three ways. First, the calculations: the formula sheet helps with speeds, feeds, machining time and threads, but tapers, sine bars and indexing have to come from memory, and 25 to 35 per cent of the questions are critical thinking, which the preparation guide says can need more than one calculation. Second, the scope: benchwork, power saws, drill presses, conventional lathes and milling machines, precision grinding, and CNC programming, set-up and operation, at the level of a journeyperson anywhere in Canada. If your shop is all CNC or all manual, part of the exam is work you do not do every day. Third, the pace and the margin: about 1 minute 47 seconds a question, and 40 wrong answers is the most you can afford.
The Red Seal Program publishes no pass rate, for this trade or any other, and it does not rank the trades by difficulty. The provincial figures we found, each counted a different way, are set out in how hard is the Red Seal exam. What the published breakdown does tell you is where the risk sits: a weak spot in lathes, milling or CNC costs the most, because each is about a fifth of the exam.
10How much does a Red Seal machinist make?
For Ontario, Skilled Trades Ontario's 2025 trade report for General Machinist (429A) gives an annual range of $55,000 to $78,000 and an hourly range of $28 to $40, from Workforce Planning Ontario's Labour Market Insights Report 2025. The report notes that its figures apply to the National Occupational Classification code 72100 and that other trades or occupations may be included, so they describe the machinist occupation in Ontario, not Red Seal holders alone. Pay elsewhere in Canada is not covered by that report.
11How should you prepare?
Follow the weights. In order: E and F (28 each), H (27), A (13), B and G (11 each), D (9) and C (8). Blocks E, F and H together are 83 of 135 questions, 61.5 per cent. The five largest tasks, setting up milling machines (15), setting up lathes (14), operating lathes (14), operating milling machines (13) and CNC programming (12), hold 68 of the 135 questions, 50.4 per cent.
You need 95 correct answers. A perfect score on E, F and H still leaves you 12 short, and a more realistic 62 of those 83 means you need 33 of the other 52. Give E, F and H about 60 per cent of your time, and do not skip the small blocks: A, B, C, D and G are 52 questions between them.
Rate yourself on each of the 20 tasks with the three levels in the Red Seal Self-Assessment Guide for Machinist and write down how many questions you expect to get right; a low rating on a large task is your first priority. Work the formula sheet until choosing the right formula is automatic, then practise the calculations it leaves out: taper per foot and the compound rest angle, a sine bar build-up, and an indexing calculation for the dividing head. Do them in both inch and metric. There is no penalty for a wrong answer, so answer everything. For a full method, see how to study for the Red Seal exam.
Official links: the Machinist Red Seal Occupational Standard page, the 2018 standard as a PDF, the exam information page (the breakdown, the question mix with the three examples, the formula sheet and the acronym list) and the Self-Assessment Guide.
12Questions people ask
- How many questions are on the Machinist Red Seal exam?
- The Machinist Red Seal exam (General Machinist, 429A, in Ontario) has 135 multiple-choice questions and a four-hour writing time, about 1 minute 47 seconds per question. Each question has four options and one correct answer, and the pass mark is 70 per cent, which means 95 correct answers. You can miss 40 and still pass. The questions come from eight blocks; the largest are conventional lathes and conventional milling machines with 28 questions each and CNC machines with 27.
- Is there a formula sheet on the Machinist Red Seal exam?
- Yes. A two-page formula sheet and an acronym list are provided at the sitting. The sheet gives π = 3.1416 and fourteen formulas: bend allowance for a 90 degree bend, cutting force, external and internal thread depth (imperial), feed rate per minute, measurement over wires (two forms), pitch diameter (metric), rpm (imperial and metric), tap drill size, machining time for a lathe and for a mill, and wire size. It has no taper, sine bar, indexing, gear or trigonometry formulas, so those have to be known from memory.
- How much CNC is on the Machinist Red Seal exam?
- CNC machines are Block H, 27 of the 135 questions, which is 20 per cent of the exam: CNC programming 12 questions, setting up CNC machines 8 and operating them 7. Conventional lathes and conventional milling machines carry 28 questions each, so manual machining is the larger share, and the occupational standard says conventional machining skills continue to form the basis of the trade.
- Is the Machinist Red Seal exam in inch or metric?
- Both systems appear in the material the Red Seal Program provides. The formula sheet has separate imperial and metric rpm formulas, imperial thread depth formulas and a metric pitch diameter formula, and the acronym list includes in., sfpm, ipm and tpi as well as mm, m/min and mm/min. The Program's published critical thinking example is in inches. It does not publish what share of the questions use each system, so prepare to calculate in both.
- Is 429A General Machinist the same as the Machinist Red Seal?
- Yes. Machinist is the Red Seal name for the trade. Ontario calls it General Machinist, and 429A is Ontario's trade code. It is one interprovincial exam of 135 questions built on the 2018 Red Seal Occupational Standard, and passing it in Ontario earns the Certificate of Qualification with the Red Seal endorsement from Skilled Trades Ontario. The trade is non-compulsory in Ontario, with an 8,000-hour apprenticeship (7,280 hours on the job and 720 in school).
- Is the Machinist Red Seal exam hard?
- It is demanding mainly because of its calculations and its breadth. Between 25 and 35 per cent of the 135 questions are critical thinking and 50 to 60 per cent are procedural, the formula sheet has no taper, sine bar or indexing formulas, and the exam covers benchwork, sawing, drilling, conventional lathes and milling machines, precision grinding and CNC. You need 95 correct answers (70 per cent). The Red Seal Program publishes no pass rate for the trade and does not rank trades by difficulty.
13Sources
- Red Seal Program: Machinist exam information: 135 questions, the question count for each major work activity and task, the question mix with one example of each question type, and the formula sheet and acronym list provided with the exam.
- Red Seal Program: description of the Machinist trade: the Red Seal trade name, Ontario's title (General Machinist), and the trades the standard names as overlapping.
- Red Seal Program: Red Seal Occupational Standard, Machinist: the standard's products: the full standard, the trade profile and the exam information page.
- Red Seal Occupational Standard: Machinist (2018, PDF): the 8 major work activities, 20 tasks and 110 sub-tasks, the task descriptors and range of variables, the trends section and the harmonization recommendations.
- Red Seal Program: Machinist formula sheet (PDF): the abbreviations, the constant and the fourteen formulas provided with the exam.
- Red Seal Program: Machinist acronyms (PDF): the acronym list provided with the exam.
- Red Seal Exam Self-Assessment Guide: Machinist (PDF): the question count per major work activity and task, the rounded percentages, and the three-level self-rating used in the preparation section.
- Red Seal Exam Preparation Guide: exam format, pass mark, writing time, question types, exam supplies and exam room rules.
- Skilled Trades Ontario: General Machinist: the Ontario trade name and code (General Machinist, 429A), its non-compulsory status, the apprenticeship hours, and the 2025 trade report linked from the page (entry level, certificates issued, pay ranges).
- Skilled Trades Ontario: Trade Equivalency Assessment: the Ontario route for experienced workers who did not complete an Ontario apprenticeship.
The question counts were checked against the Red Seal Program's exam information page and Self-Assessment Guide for Machinist on October 3, 2026, and the task lists and range of variables come from the 2018 Red Seal Occupational Standard, whose task numbering both documents use. The formula list was read from the Program's formula sheet. The Ontario name, status, hours, certificate count and pay ranges come from Skilled Trades Ontario's General Machinist trade page and its 2025 trade report. If the Red Seal Program changes the breakdown, its page is the final word. If you find one of ours out of date, tell us.
Related: Machinist (429A) practice exam · Free Machinist practice questions · Tap drill chart and calculator (UNC, UNF, metric) · How hard is the Red Seal exam · How many questions are on the Red Seal exam · Red Seal exam pass mark · Red Seal exam fees by province · How to challenge the Red Seal exam · 433A Millwright exam guide · All guides
14Practice for this exam
TicketPrep Machinist practice tests are weighted to the breakdown above, block by block, and every answer is explained, all four options. You can try five sample questions with no account.
Ten free questions per trade, no account: free practice questions. How our questions are written and checked: how our questions are made.