This free CAST test study guide teaches the — the pre-employment aptitude test that electric and energy utilities use to screen candidates for construction and skilled-trade jobs like lineworker, substation technician, and meter service.[1]It’s the test you take to get hired into utility craft work.
It’s interactive, not a wall of text: every section has a built-in checkpoint quiz, hover-able glossary terms, worked graphic-arithmetic and mechanical examples, labeled diagrams, and concept questions, so you learn by doing.
Work through the four section modules, test yourself at each checkpoint, then round out your free CAST prep with our practice questions and flashcards.
CAST Test Snapshot
The CAST is published by the and administered by individual utilities as a hiring screen.[2] One important nuance: EEI revised the test into (© 2020), which keeps the first three sections but replaces with the , a work-style questionnaire.[1]Most prep sites still describe the older four-cognitive-section CAST — this guide teaches all four cognitive sections so you’re ready for either version, and flags the difference along the way.
| Section | Questions | Time | What it tests |
|---|---|---|---|
| Graphic Arithmetic | 16 | 30 min | Math problems solved from drawings/prints |
| Mechanical Concepts | 44 | 20 min | Pulleys, levers, gears, fluids, forces |
| Reading for Comprehension | 32 | 30 min | Answering questions from work passages |
| Mathematical Usage (legacy) | 18 | 7 min | Formulas, conversions, percentages, ratios |
| Work Preferences Inventory (CAST-R) | 105 | 30 min | Work-style questionnaire — no right answer |
The first three sections are stable across both versions. The legacy CAST adds Mathematical Usage; the current CAST-R adds the Work Preferences Inventory instead.[3] Scores from all sections are combined into a single — an index that predicts your probability of success on the job — and the hiring utility decides which score it accepts.[1] This guide groups the cognitive material into four section modules:
EEI’s Construction and Skilled Trades (CAST) test has four sections. Mechanical Concepts and Reading for Comprehension are the two biggest; Graphic Arithmetic and Mathematical Usage are the applied-math sections. Every question is multiple choice.
- Read a scaled drawing or blueprint
- Pull the numbers off the figure
- Then do the arithmetic
- Pulleys, levers, gears
- Fluids, pressure & forces
- How simple machines behave
- Read a work-related passage
- Answer from the text only
- Main idea, detail & inference
- Apply a given formula
- Unit conversions & rates
- Percentages, ratios & proportions
Mechanical Concepts is the largest section by question count, and Graphic Arithmetic plus Mathematical Usage are the two applied-math sections — so the math and mechanical reasoning carry the most weight in your prep:[4]
Percentages above are of the ~110 legacy cognitive questions, to show where to spend your time. On CAST-R the Work Preferences Inventory replaces Mathematical Usage and is answered honestly, not studied. Build the math and mechanical skills first — they’re where preparation pays off most.[3]
1 · Graphic Arithmetic
is math you read off a drawing. The section gives you prints or diagrams — typically two drawings, each followed by several questions — and asks you to pull dimensions and other values from the figure, then do the arithmetic.[3] A calculator is permitted on this section in the official CAST-R version.
Reading scaled drawings & prints
The first skill is reading the figure exactly. Find the (for example, 1 inch = 10 feet), the labeled dimensions, and any notes. Then convert a drawing measurement to a real measurement by multiplying by the scale.
Watch the figure’s own warning:CAST drawings are often labeled “not drawn exactly to scale,” so trust the printed dimensions and the stated scale, not how long a line looks.[3]
Graphic Arithmetic gives you a drawing with a scale, then asks for a real-world value. The skill is reading the figure correctly, then multiplying by the scale.
Rule: real value = drawing measurement × scale. Watch the units — convert each dimension before you multiply for an area.
Computing lengths, areas & ratios
Once the dimensions are in real units, the math is straightforward: add lengths along a path, multiply length × width for a rectangular area, or set up a ratio. For an area, convert both dimensions to real units first, then multiply — never multiply the drawing inches and convert at the end, because area scales by the square of the linear factor.
| You're asked for | Set it up as |
|---|---|
| A real length | drawing length × scale |
| A rectangular area | real length × real width |
| Total distance along a path | sum of the real segment lengths |
| A scale ratio | drawing length ÷ real length (same units) |
| A reduced/enlarged size | original × linear scale factor |
Graphic arithmetic traps
The most common traps are misreading the scale (using 1 inch = 10 feet as if it were 1 foot), measuring a line by eye on a not-to-scale drawing instead of using the printed dimension, and mixing up area and perimeter. Always answer the exact question asked — a length, an area, or a count.
Checkpoint · Graphic Arithmetic
Question 1 of 8
If a blueprint has a scale of 1 inch equals 30 feet, and a room on the blueprint is 4 inches by 6 inches, what is the actual size of the room in feet?
2 · Mechanical Concepts
is the signature, largest CAST section — 44 questions on how simple machines and forces behave, each usually shown as a pictured situation with three answer choices.[3] The unifying rule for every machine below: = output force ÷ input force, and a machine never gives free work — force you save is paid back in distance.
Pulleys & mechanical advantage
A ’s mechanical advantage equals the number of rope segments that support the load. A fixed pulley (one segment) only changes direction — no force saved. A movable pulley (two segments) halves the effort. A combines them for more.
The single most-tested mechanical idea on the CAST. To find the effort, divide the load by the number of supporting rope segments. More segments = less effort, but more rope to pull.
Rule: effort = load ÷ number of supporting rope segments. A machine never gives free work — force saved is paid back in distance.
Levers & the law of the lever
A is a bar pivoting on a . Identify its class by what sits in the middle. The law of the lever: effort × effort-arm = load × load-arm — so a longer effort arm lets a small effort move a large load.
Identify a lever by what sits in the middle. Law of the lever: effort × effort-arm = load × load-arm — a longer effort arm multiplies your force.
Gears, belts & wheel-and-axle
Two externally meshed gears always turn in opposite directions. The is the driven gear’s teeth divided by the driver’s. A larger gear turns slower but with more ; a smaller gear turns faster with less. Belts and a follow the same trade between speed and force.
Two externally meshed gears always turn in opposite directions. The gear with more teeth turns slower but with more force (torque).
Gear ratio = driven teeth ÷ driver teeth = 60 ÷ 20 = 3 : 1. The driven gear turns at one-third the speed with three times the torque. An idler gear between them flips direction but does not change the ratio.
Fluids, pressure & forces
use a confined fluid to multiply force. says pressure is the same throughout the fluid, and force = pressure × area — so a larger output piston produces a larger force. The same “trade force for distance” logic governs the , wedge, and screw.
Pressure in a confined fluid is the same everywhere, so a small piston and a large piston share one pressure. The large piston’s greater area turns that pressure into a much larger force.
Force = pressure × area. A 10× bigger output area gives a 10× bigger force (mechanical advantage = A₂ ÷ A₁). This is how hydraulic jacks, brakes, and lifts work.
Checkpoint · Mechanical Concepts
Question 1 of 10
A pulley system is designed to lift a 200-pound weight using a force of 50 pounds. How many pulleys are needed in the system?
3 · Reading for Comprehension
tests whether you can understand written work material — the CAST gives you a few work-related passages, each followed by multiple-choice questions you answer from the text only.[3] Utility craft work runs on written orders and procedures, so this skill is job-real.
Reading work-related passages
Passages read like real workplace material — a procedure, a safety rule, an equipment description. The skill is to find exactly what the passage says and use it, not what you already know about the trade. When a passage states a rule, separate the condition (when it applies) from the required action (what must be done).
Detail, main idea & inference
Reading questions come in three flavors. A detail question is answered word-for-word in the text. A main-idea question asks what the whole passage is about. An inferencequestion asks for a logical conclusion the passage supports but doesn’t state outright.
| Question type | What it asks | How to attack it |
|---|---|---|
| Detail / fact | Something stated in the text | Scan for the keyword, then read the exact sentence |
| Main idea | The passage's overall point | Look at the first/last sentence; ignore minor details |
| Inference | A conclusion the text supports | Combine stated facts; don't add outside assumptions |
Checkpoint · Reading for Comprehension
Question 1 of 10
After reading a detailed passage about the construction of a suspension bridge, which of the following components is NOT typically involved in the tension and compression dynamics described?
4 · Mathematical Usage
is applied arithmetic and formula work— on the legacy CAST it’s a fast section (18 questions in about 7 minutes), so the skill is quick, accurate setup, not heavy computation.[4]The current CAST-R uses the Work Preferences Inventory in its place, but these math skills still help on Graphic Arithmetic, so they’re worth drilling either way.
Applying formulas & equations
Many items give you a formula (or expect a standard one) and ask you to plug in and solve, or to solve a short equation. Translate: name what’s asked, substitute the numbers, then solve step by step.
| Problem type | Set it up as |
|---|---|
| Distance / rate / time | distance = rate × time |
| Rectangular area | area = length × width |
| Solve a linear equation | isolate the variable step by step |
| Average (mean) | sum of values ÷ count |
| Volume of a box | length × width × height |
Unit conversions & rates
Conversions are everywhere in utility work. Use — multiply by a factor written so the old unit cancels. Match units before you calculate a rate (convert minutes to hours, inches to feet) so the answer comes out in the unit asked.
Percentages, ratios & proportions
To find a percent of a number, multiply by its decimal (15% → 0.15). For percent change, divide the change by the original value and multiply by 100. For a , set two ratios equal and cross-multiply.
| Fraction | Decimal | Percent |
|---|---|---|
| 1/2 | 0.5 | 50% |
| 1/4 | 0.25 | 25% |
| 3/4 | 0.75 | 75% |
| 1/3 | 0.333… | ≈ 33% |
| 1/5 | 0.2 | 20% |
| 1/8 | 0.125 | 12.5% |
Checkpoint · Mathematical Usage
Question 1 of 8
A construction project requires 3.5 cubic yards of concrete per hour over an 8-hour workday. If concrete is ordered in cubic meters, how many cubic meters of concrete are needed for one day, given 1 cubic yard equals 0.764 cubic meters?
CAST Scores Explained
The CAST does not give you a per-section pass/fail. Instead, EEI combines your section scores into a single — on CAST-R reported as an from 1 to 10 — that predicts your probability of success on the job.[1] There is no penalty for wrong answers, so you should answer every question, even when guessing.
EEI combines your four sections into a single Total Test Score and reports it as a recommendation band — not a per-section pass/fail. The employer chooses the cutoff it accepts, so a higher score is always safer. These bands are general guidance, not an official cut score.
Because the employer sets the cutoff and may rank candidates, aim for the highest score you can— not just “recommended.”
There is no single national passing score: each hiring utility sets the minimum score it accepts for a role, and competitive jobs want a higher one.[4] Because the employer chooses the cutoff and may rank candidates, your goal is the highest Total Test Score you can earn — not just clearing the floor.
How to Use This Study Guide
A study guide is a map, not the whole territory — use it alongside timed practice and our free tools. Because the CAST is separately timed by section and rewards applied skill, part of your prep is strategy (pacing each section) and part is skill (the math and mechanical core).
The CAST rewards applied skill, not memorized trivia. Run this loop until each step is automatic.
- 1. Learn the four sectionsGraphic Arithmetic, Mechanical Concepts, Reading for Comprehension, and Mathematical Usage — know exactly what each one asks.
- 2. Master Mechanical Concepts firstIt's the largest section. Lock in pulleys, levers, gears, fluids, and forces — the rules repeat across many questions.
- 3. Drill the math both waysGraphic Arithmetic = read a drawing then calculate; Mathematical Usage = apply a given formula and convert units. Practice both.
- 4. Practice reading for the text onlyAnswer Reading for Comprehension items from what the passage actually says — not outside knowledge.
- 5. Rehearse under timed conditionsEach section is separately timed. Take full, timed practice runs so your pacing is automatic on test day.
- 6. Aim for the highest Total Test ScoreThe employer picks the cutoff, so a strong score beats a bare pass — push your weakest section up.
- 1
Learn the four sections
Work the modules so Graphic Arithmetic, Mechanical Concepts, Reading for Comprehension, and Mathematical Usage are all familiar.
- 2
Take the checkpoints
The quick check at the end of each module exposes what didn't stick.
- 3
Drill the gaps
Send your weakest section straight into the free practice questions and flashcards — Mechanical Concepts repays the most practice.
- 4
Rehearse under timed conditions
Take full, timed practice runs so your pacing on each separately-timed section is automatic on test day.
CAST Concept Questions
The skills the CAST actually measures — at least one per section, led by mechanical concepts. Tap any card for a short, exam-ready answer backed by an authoritative source, then test yourself on them as flashcards.
CAST Glossary
Quick definitions for the terms you’ll see most across the CAST test:
- Block and tackle
- A system of fixed and movable pulleys whose mechanical advantage equals the number of rope segments supporting the load.
- CAST
- The Construction and Skilled Trades selection test, published by the Edison Electric Institute (EEI). Electric and energy utilities use it to screen candidates for construction and skilled-trade jobs such as lineworker, substation technician, and meter service.
- CAST-R
- The revised version of the CAST (© 2020 EEI). It keeps Graphic Arithmetic, Mechanical Concepts, and Reading for Comprehension, and replaces the Mathematical Usage section with the Work Preferences Inventory, a work-style questionnaire.
- Dimensional analysis
- Converting units by multiplying by a fraction written so the unwanted unit cancels and the wanted unit remains — the safe way to handle CAST unit conversions.
- EEI
- The Edison Electric Institute — the trade association of U.S. investor-owned electric utilities. It develops and validates the CAST and a family of energy-industry employment tests (POSS, MASS, TECH, and others).
- Fulcrum
- The fixed pivot point a lever turns on.
- Gear ratio
- The driven gear's number of teeth divided by the driver gear's teeth. A higher ratio means the driven gear turns slower with more torque.
- Graphic Arithmetic
- The CAST section that gives you a drawing or print and asks you to solve arithmetic problems using information read from it — distances, areas, and ratios.
- Hydraulics
- Using a confined fluid to transmit and multiply force. Force equals pressure times area, so a larger output piston produces a larger force.
- Idler gear
- A gear placed between the driver and driven gear. It reverses the direction of rotation but does not change the overall gear ratio.
- Inclined plane
- A ramp that reduces the force needed to raise a load by spreading the work over a longer distance; its mechanical advantage is slope length divided by height.
- Index score
- The CAST-R's combined score on a 1–10 scale (higher is more favorable). It expresses a probability of job success; the hiring utility decides which value it accepts.
- Lever
- A rigid bar that pivots on a fulcrum. Effort × effort-arm equals load × load-arm, so a longer effort arm multiplies your force.
- Mathematical Usage
- A CAST section (in the legacy version) that asks you to apply a given formula and do unit conversions, rates, percentages, and ratios. The current CAST-R uses the Work Preferences Inventory in its place.
- Mechanical advantage
- The factor by which a simple machine multiplies your input force: output force divided by input force. A machine never gives free work — force saved is paid back in distance.
- Mechanical Concepts
- The CAST section that tests understanding of mechanical principles — pulleys, levers, gears, fluids, and forces — usually with a pictured situation and three answer choices.
- Pascal's principle
- Pressure applied to a confined fluid is transmitted equally throughout it, letting a small force on a small piston create a large force on a large piston.
- Pitch
- The distance a screw advances along its axis in one complete turn. Total advance equals pitch times the number of turns.
- Proportion
- A statement that two ratios are equal (a/b = c/d). Solve for a missing value by cross-multiplying.
- Pulley
- A grooved wheel with a rope. A fixed pulley changes the direction of a force (mechanical advantage 1); a movable pulley supports the load on two segments (mechanical advantage 2).
- Reading for Comprehension
- The CAST section that gives you work-related passages and asks multiple-choice questions answered from the text alone.
- Scale
- The ratio that tells you how a length on a drawing relates to a real length (for example, 1 inch = 10 feet). Multiply a drawing measurement by the scale to get the real value.
- Torque
- A turning or twisting force, equal to the applied force times the distance from the pivot (the lever arm).
- Total Test Score
- The single combined index score the CAST reports, formed by combining the section scores. It predicts the probability of success on the job rather than giving a per-section pass/fail.
- Wheel and axle
- A simple machine in which a large wheel turns a smaller axle (or vice versa). Its mechanical advantage equals the wheel radius divided by the axle radius.
- Work Preferences Inventory (WPI)
- A behavioral/work-style questionnaire on the current CAST-R that asks how strongly you agree with statements about how you like to work. It has no right or wrong answers and is not an aptitude test.
Free CAST Test Study Materials & Resources
Everything you need to prepare for the CAST is free here — no paywall, no sign-up. This guide is the foundation; pair it with the rest of our free CAST study materials for active recall and timed practice:
- CAST Practice Test — exam-style questions across all four sections, with explanations.
- CAST Flashcards — active-recall decks for mechanical rules, graphic-arithmetic setup, conversions, and reading strategy.
CAST Study Guide FAQ
The CAST is built from four sections. In the widely studied version they are Graphic Arithmetic (16 questions), Mechanical Concepts (44), Reading for Comprehension (32), and Mathematical Usage (18) — about 110 questions. The current CAST-R replaces Mathematical Usage with the Work Preferences Inventory, a work-style questionnaire. Confirm your version with the utility you're applying to.
The current CAST-R is administered in approximately two hours. The legacy four-cognitive-section CAST runs roughly 87–90 minutes, with each section separately timed (Graphic Arithmetic 30 minutes, Mechanical Concepts 20, Reading for Comprehension 30, Mathematical Usage 7).
EEI combines your section scores into one Total Test Score — an index, reported on a 1–10 scale on CAST-R — that predicts your probability of success on the job. It is not a per-section pass/fail, and there is no penalty for wrong answers, so you should answer every question. Each hiring utility sets the minimum score it accepts.
Graphic Arithmetic (solving math problems from drawings and prints), Mechanical Concepts (pulleys, levers, gears, fluids, and forces), Reading for Comprehension (answering questions from work-related passages), and Mathematical Usage (applying formulas, conversions, percentages, and ratios). The current CAST-R also includes the Work Preferences Inventory in place of Mathematical Usage.
Yes on at least the Graphic Arithmetic section — the official EEI CAST-R brochure states a calculator is permitted there. Some prep sites disagree, and policy can vary by version and by employer, so confirm exactly what's allowed with the utility administering your test. No other study aids or electronics are permitted.
Candidates applying to electric and energy utilities for construction and skilled-trade jobs — lineworker, transmission and distribution craft, substation technician, facilities and equipment repair, machining and vehicle repair, and meter service. EEI validated the CAST across six job categories using a consortium of investor-owned electric companies.
Usually yes, after a waiting period set by the utility, not by EEI. Many employers require roughly a 30-day minimum between attempts and may limit how many times you can test in a year. The often-cited 'six-month' wait actually belongs to EEI's TECH test, not the CAST — check your employer's specific policy.
The CAST-R is the revised, current version (© 2020 EEI). It keeps Graphic Arithmetic, Mechanical Concepts, and Reading for Comprehension, but replaces the Mathematical Usage section with the Work Preferences Inventory — a work-style questionnaire with no right or wrong answers. Most prep sites still describe the older CAST, so verify which one you'll take.
Work through the four section modules — Graphic Arithmetic, Mechanical Concepts, Reading for Comprehension, and Mathematical Usage — take each checkpoint to find your gaps, then drill your weakest area with our free practice questions and flashcards. Mechanical Concepts is the largest section, so give it the most time.
Yes — the full guide, the checkpoints, the glossary, the practice questions, and the flashcards are 100% free, with no account required.
References
- 1.Edison Electric Institute. “CAST-R Test Brochure (Construction and Skilled Trades, Revised).” Edison Electric Institute. ↑
- 2.Edison Electric Institute. “Employment Test Batteries.” Edison Electric Institute. ↑
- 3.Edison Electric Institute. “CAST-R Student Practice Tests (© 2020 EEI).” Southern Company (EEI-licensed). ↑
- 4.Southern California Edison. “Information Guide — EEI CAST (Test #5108).” Southern California Edison (EEI-licensed). ↑
Sources for the concept answers
Every answer in the CAST concept questions above is drawn from an authoritative source:
- Wikipedia. “Block and tackle.” Wikipedia.
- Wikipedia. “Pulley.” Wikipedia.
- Wikipedia. “Gear train.” Wikipedia.
- Wikipedia. “Lever.” Wikipedia.
- OpenStax. “Pascal's Principle and Hydraulics (University Physics).” OpenStax.
- Wikipedia. “Inclined plane.” Wikipedia.
- Wikipedia. “Scale (ratio).” Wikipedia.
- Wikipedia. “Conversion of units.” Wikipedia.
- Wikipedia. “Speed.” Wikipedia.
- Wikipedia. “Percentage.” Wikipedia.
- Wikipedia. “Ratio.” Wikipedia.
- Wikipedia. “Reading comprehension.” Wikipedia.
- Wikipedia. “Torque.” Wikipedia.
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