Measuring Tools | ASVAB Shop Information

Measuring Tools

Shop questions often ask which tool fits a job. This page covers the tools used to measure and lay out work before cutting or assembly.

Measuring and layout tools

These tools help you take accurate measurements and check angles before cutting, assembling, or installing parts.

Nine labeled measuring tools: a tape measure, a steel ruler, a micrometer, a caliper with a main scale and a sliding vernier scale, a depth gauge, a level, a measuring wheel, a steel square, and a protractor marked from 0 to 180 degrees in both directions. — ASVAB Measuring tools

Tool	Used for
Tape measure	Measuring lengths and distances. It is especially useful when a flexible measuring tool is needed such as measuring wire runs or equipment clearances. It is also useful for measuring large distances.
Steel ruler	Measuring short, rigid materials with precision. Its straight edge also serves as a guide for marking and making straight cuts.
Micrometer	Measuring the thickness or diameter of small parts with very high precision, such as sheet metal, wire, or bolts.
Caliper	Measuring outside and inside diameters of cylindrical objects such as pipes. It also measures the thickness of materials or components such as sheet metal.
Depth gauge	Measuring the depth of holes, slots, and recesses. A tread depth gauge checks tire tread depth.
Level	Determining whether a surface is level or plumb. Commonly used when setting posts, installing equipment, or ensuring proper drainage.
Measuring wheel	Measuring long distances quickly, such as runways, roads, utility lines, or property boundaries.
Steel square	Marking and checking $90°$ angles to ensure accurate layouts, cuts, and assembly of materials.
Protractor	Measuring and marking angles other than $90°$ , such as for map reading, machining, or cutting materials to a specific angle.
Feeler gauge	Measuring small, uniform gaps such as spark plug gaps and valve clearances using a set of thin metal blades.
Plumb bob	Marking a true vertical line with a pointed weight hanging on a string, such as locating a point directly below another or checking that a post or wall stud is plumb.
Chalk line	Snapping a long, straight layout line across a surface, such as a cut line on a sheet of plywood or a guide line for laying floor tile.
Combination square	Checking and marking $90°$ and $45°$ angles on smaller work, such as marking a board for a square crosscut.
Sliding T-bevel	Copying an existing angle and transferring it to a workpiece, such as matching the angle where a board meets a wall.
Scriber	Scratching fine, precise layout lines into metal or wood before cutting, where a pencil line would be too wide.

Telling similar tools apart: use a micrometer for the highest precision on small parts, and a caliper for a wider range including inside diameters. Use a level for horizontal/vertical, a square for a $90°$ corner, and a protractor or T-bevel for other angles. A plumb bob marks a true vertical over a long drop where a level can’t reach, and a combination square handles both $90°$ and $45°$ on small work, while a steel square suits larger layouts. Use a tape measure for room-scale distances and a measuring wheel for very long ones.

Measuring and layout tools overview

Tools organized by function: linear measurement, precision diameter/thickness, angle checking, and line/point marking
General pattern: choose precision tools (micrometer, caliper) for small parts, large-scale tools (tape measure, measuring wheel) for long distances, and angle tools (square, protractor, T-bevel) based on whether angle is $90°$ or variable

Linear and distance measurement

Tape measure: flexible, long distances; steel ruler: short rigid measurements and straight-edge guide
Measuring wheel: very long distances (roads, property lines)
Depth gauge: holes, slots, recesses (includes tire tread gauge)

Precision diameter/thickness tools

Micrometer: highest precision for small parts (wire, bolts, sheet metal)
Caliper: broader use, measures inside/outside diameters and thickness
Feeler gauge: small uniform gaps (spark plugs, valve clearances)

Angle and squareness tools

Steel square: marks/checks $90°$ for larger layouts
Combination square: $90°$ and $45°$ on smaller work
Protractor: measures variable angles (not just $90°$ )
Sliding T-bevel: copies and transfers an existing angle

Leveling and line-marking tools

Level: checks level (horizontal) or plumb (vertical) surfaces
Plumb bob: marks true vertical over a long drop
Chalk line: snaps long straight layout lines on surfaces
Scriber: scratches fine precise lines into metal/wood before cutting

Measuring Tools

Shop questions often ask which tool fits a job. This page covers the tools used to measure and lay out work before cutting or assembly.

Measuring and layout tools

These tools help you take accurate measurements and check angles before cutting, assembling, or installing parts.

Tool	Used for
Tape measure	Measuring lengths and distances. It is especially useful when a flexible measuring tool is needed such as measuring wire runs or equipment clearances. It is also useful for measuring large distances.
Steel ruler	Measuring short, rigid materials with precision. Its straight edge also serves as a guide for marking and making straight cuts.
Micrometer	Measuring the thickness or diameter of small parts with very high precision, such as sheet metal, wire, or bolts.
Caliper	Measuring outside and inside diameters of cylindrical objects such as pipes. It also measures the thickness of materials or components such as sheet metal.
Depth gauge	Measuring the depth of holes, slots, and recesses. A tread depth gauge checks tire tread depth.
Level	Determining whether a surface is level or plumb. Commonly used when setting posts, installing equipment, or ensuring proper drainage.
Measuring wheel	Measuring long distances quickly, such as runways, roads, utility lines, or property boundaries.
Steel square	Marking and checking $90°$ angles to ensure accurate layouts, cuts, and assembly of materials.
Protractor	Measuring and marking angles other than $90°$ , such as for map reading, machining, or cutting materials to a specific angle.
Feeler gauge	Measuring small, uniform gaps such as spark plug gaps and valve clearances using a set of thin metal blades.
Plumb bob	Marking a true vertical line with a pointed weight hanging on a string, such as locating a point directly below another or checking that a post or wall stud is plumb.
Chalk line	Snapping a long, straight layout line across a surface, such as a cut line on a sheet of plywood or a guide line for laying floor tile.
Combination square	Checking and marking $90°$ and $45°$ angles on smaller work, such as marking a board for a square crosscut.
Sliding T-bevel	Copying an existing angle and transferring it to a workpiece, such as matching the angle where a board meets a wall.
Scriber	Scratching fine, precise layout lines into metal or wood before cutting, where a pencil line would be too wide.