Shop Information Study Guide for McGraw-Hill's ASVAB (page 2)
Practice problems for this study guide can be found at:
The shop information questions that appear on the ASVAB measure how much you understand about shop tools, practices, materials, and procedures. The questions may ask you to identify a particular shop tool, to tell how it is used, or to choose the correct procedure when working with wood, metal, or construction materials. If you took shop courses in high school, or if you have done any woodworking or metalworking on your own, you may already be familiar with many of the topics covered on the test. You may also have learned shop and construction tools and procedures on the job.
On the paper-and-pencil version of the ASVAB, shop questions are one part of the Auto and Shop Information test. On the CAT-ASVAB, they form a separate test of their own.
Whichever ASVAB version you take, you'll have only about half a minute to answer each shop information question, so you'll have to work fast if you want to get a good score. That's why it pays to spend time studying the test topics and tackling plenty of sample ASVAB shop information questions.
The topic review that follows will help prepare you to answer ASVAB shop information questions. It lists and describes the different tools you should know, with an emphasis on traditional hand tools. It also covers common fasteners and materials. There is also important information about tool safety.
Measurement and Layout
New projects and many repairs start with measurement and layout. This is where you amass the proper tools and materials, and mark out the cutting and drilling.
Carpenters usually use a tape measure, marked in 1/16-inch increments. The tape retracts automatically into the case, but locks in place when it must be extended for a while. The tape has a hook on the end that moves slightly for accurate inside and outside measurements. Retractable tape measures range from 6 feet to 25 feet long.
When greater accuracy is needed, machinists use a rigid steel rule. These rules are often marked in 1/32- or 1/64-inch increments and are often 1 foot long. A metric steel rule would usually be marked in 1-millimeter increments.
When even greater accuracy is needed, machinists use calipers or micrometers. Some calipers are simply two legs that can transfer a measurement to a steel rule. These calipers can take inside or outside measurements, depending on the shape of the legs. Calipers can also have straight legs.
The Vernier caliper is even more accurate, thanks to the clever Vernier system. First identify the Vernier scale and the main scale. Now look at the "0" on the Vernier scale (see Figure S-3). This is just past the third mark on the main scale, indicating 3 millimeters (mm) on this metric caliper. So the measurement is a bit more than 3 mm, but how much more? Notice that line 3 on the Vernier scale lines up with a line on the main scale. That means that you should add 0.3 mm to the measurement, making a total of 3.3 mm. (Only one mark on the Vernier scale will line up with the main scale, and it doesn't matter which line it lines up with. Remember, read the number on the Vernier scale to get the right-hand digit in the measurement.)
Micrometers are even more accurate than Vernier calipers, but they are usually designed to read only in a certain range, say up to 1 inch, or 1 inch to 2 inches. Unlike a Vernier caliper, where you slide the adjuster, you turn a screw on a micrometer.
Layout often calls for square (90°) lines. A carpenter's square is used to draw these lines: When you hold one leg against the edge of a board, the second makes a square line across the board. A smaller version is called the try square.
You may also see a sliding bevel, which has a metal leg fastened to a wooden block. By loosening the adjustment screw, you can set the tool to mark almost any angle. Sliding bevels can be used to transfer angles from place to place.
The easiest way to tell if something is level (horizontal) or vertical (plumb) is with a level, sometimes called a spirit level. Levels use glass or plastic tubes that are curved or slightly swollen in the middle. When the bubble in the liquid (spirit) is centered, the level is horizontal or vertical.
Cutting and Shaping
After the layout step is done, it's time to cut and shape the materials. We'll take up woodworking tools first, then metalworking tools.
Sharp hand saws are the most basic way to cut wood. Saws cut a kerf that is wider than the blade itself; the kerf allows the saw to move freely through the cut. Crosscut saws are designed to cut at 90° to the grain, while ripsaws cut parallel to the grain. Ripsaws have larger teeth. Backsaws have a rigid steel backing that improves accuracy; they are used in miter boxes that guide them for 45° or 90° cuts.
Keyhole saws are made to cut complicated profiles. An electric version is called the jigsaw. A coping saw has a thin blade held in a P-shaped handle. The saw is used to cut molding.
An electric circular saw, usually with a 7-1/4-inch-diameter blade, is much faster for cutting wood, especially for ripsawing, and for sawing plywood or other panels. These saws are dangerous; read the instruction manual carefully.
Wood chisels, sold in widths from 1/4 inch to 1-1/2 inches, cut wood when they are struck with a hammer or mallet.
A hand plane removes thin strips of wood and is used to shape, smooth, or reduce the size of boards. It's especially useful for removing saw marks from the edge of a board. The "jack" plane is a generalpurpose type of hand plane.
A hacksaw has a replaceable metal blade with small teeth and is that is used for cutting iron, steel, and other, softer metals. Choose a blade with finer teeth for thinner metal, and one with larger teeth for thicker metal. The hacksaw should cut on the forward stroke.
Tin snips cut steel, copper, or aluminum sheet metal, using a shearing action. Some snips have replaceable blades; others can be sharpened. Special snips are designed to cut curves.
A right-angle grinder can polish metal before painting, or otherwise smooth or shape metal. Grind toward the edge of the wheel; do not hold it flat to the surface of the metal. The same tool will also drive a wire brush for removing rust.
A pipe cutter—used for copper, not steel, pipe—has a sharp cutting wheel. Gradually tighten the handleas you rotate the tool around the pipe.
Taps and dies cut or restore threads in metal. A die cuts threads on a rod; a tap cuts threads in a hole drilled in a plate. Either tool can be used to restore mangled threads. Both taps and dies cut only one diameter and pitch (number of threads per inch). To select a die, you must know the outside diameter (O.D.) of the pipe.
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