ASVAB Shop Information — Basic Plumbing and Electrical Questions

Hand saw types and uses: CROSSCUT SAW cuts ACROSS wood grain; teeth shaped like knives that sever fibers; typically 8-12 TPI (teeth per inch); general lumber cuts across grain. RIP SAW cuts WITH grain (parallel to fibers); chisel-shaped teeth scoop out wood; coarser teeth at 5-7 TPI; faster cuts along grain. COPING SAW has narrow blade in U-shaped frame; designed for tight curves and intricate shapes; blade can be rotated; great for trim work, dovetails, decorative cuts. HACKSAW has fine-toothed metal-cutting blade; replaceable blades typically 18-32 TPI; cuts metal, plastic, pipe. BACK SAW has rigid spine; precise straight cuts; types include MITER SAW (in miter box for angle cuts), TENON SAW (for joinery cuts), DOVETAIL SAW (small, fine teeth for dovetail joints). JAPANESE SAW (nokogiri) cuts on PULL stroke (Western saws cut on push); thinner kerf, more control. KEYHOLE or COMPASS SAW has pointed blade for starting cuts in middle of material. BOW SAW has large bow-shaped frame for cutting logs and firewood. POWER SAW EQUIVALENTS for curves: JIG SAW (handheld reciprocating blade) handheld; SCROLL SAW (benchtop) very fine intricate cuts; BAND SAW continuous loop blade for curves and resawing. TEETH PER INCH (TPI) rule: more teeth means smoother but slower cut; fewer teeth means rougher but faster cut. KERF is the slot the saw cuts; SET refers to teeth alternately bent slightly left and right to create a kerf wider than blade body, preventing binding. ASVAB SI commonly tests recognizing saw types from images and matching saws to appropriate tasks like cutting along or across grain, metal, or curves.

Hammer types and applications: CLAW HAMMER is most common; striking face on one end, curved claw on the other for pulling nails using leverage; common sizes are 16 oz for general carpentry and 20-24 oz for framing; steel, fiberglass, or wood handle; FRAMING HAMMER has straight (rip) claw and waffle face for grip on nails, sometimes magnetic nail starter. BALL-PEEN HAMMER has flat face on one end and rounded ball on the other; for metalwork; the ball end peens (deforms) metal, sets rivets, shapes metal. CROSS-PEEN or STRAIGHT-PEEN has wedge-shaped narrow end for starting nails or working into tight spaces; blacksmith hammers. SLEDGEHAMMER is large heavy hammer (2-20 lb) for demolition, driving stakes, breaking concrete; long handle for two-handed swinging. MALLET is softer-headed hammer (rubber, wood, rawhide, plastic); strikes without damaging workpiece; great for assembling joinery, chiseling (wood mallet on wood chisels), driving stakes, automotive (rubber mallet). DEAD-BLOW HAMMER has hollow head filled with shot or sand; reduces rebound and prevents marring; for automotive, machinery work, persuading parts together without damage. TACK HAMMER is small and often magnetic for upholstery and small nails. BRICK or MASON HAMMER has chisel-like end for scoring bricks. DRYWALL HAMMER has milled face and hatchet-like back for drywall installation. SOFT-FACE or NYLON HAMMER is for delicate work, jewelry, electronics. Using hammers correctly: grip near end of handle for maximum leverage and swing arc (beginners often choke up too much); strike with FACE square to nail head (angled strikes cause bent nails); use arm and shoulder motion, not just wrist; let hammer weight do the work, don't muscle it; eye protection is mandatory because nails can fly back and debris can come off struck surfaces. REMOVING NAILS with claw hammer: hook claw under nail head, pry handle backward; for deeply driven nails place a wood block under the hammer to increase leverage and protect the surface. Larger nails may require a pry bar or cat's paw.

Match driver type to screw recess: SLOTTED (flat-head) has straight slot; one of the oldest types; can slip out (cam-out) easily under torque; flat-blade screwdriver fits; sizes by blade width (1/8 inch, 3/16 inch, 1/4 inch common). PHILLIPS has cross-shaped (+) recess; designed to cam-out at high torque (originally as a safety/torque-limiting feature); Phillips screwdriver fits; sizes #00, #0, #1, #2 (most common for general work), #3 (large); #2 fits most household and electronic screws. POZIDRIV is similar to Phillips but with additional radial lines/ribs; less prone to cam-out; common in European applications and electronics; can damage Phillips bits if forced. ALLEN or HEX has hexagonal recess; uses hex key (Allen wrench) L-shaped tool; very common in furniture (IKEA), bicycles, machinery; metric and SAE sizes. TORX (STAR) has six-pointed star recess; designed for high torque without cam-out; common in automotive, electronics, machinery; sizes T1 (very small) to T100; security torx has a center pin to prevent standard torx bits from working. SQUARE or ROBERTSON has square recess; Canadian invention; very good engagement; common in cabinetry, decking; sizes R0 (yellow), R1 (green), R2 (red), R3 (black). SPLINE or 12-POINT is for automotive and aerospace. TRI-WING, TORQ-SET, BRISTOL are security screws used in electronics and aerospace; require specialized drivers. PROPER USE: match the size; press down firmly while turning (downward force) since many screws back out easily because of insufficient pressure; use straight (angled drivers cam out easily); longer handle equals more torque; don't hammer on a screwdriver unless it's a special impact/striking screwdriver. STRIPPED SCREWS: when recess is damaged, remedies include rubber band between driver and recess; tapping driver to engage; screw extractor (drill into screw head, then back out with reverse-thread extractor); left-handed drill bits (can grab and unscrew while drilling); pliers or Vise-Grips on protruding head. RIGHTY-TIGHTY, LEFTY-LOOSEY: for most screws clockwise tightens and counterclockwise loosens (viewed from driver end). Exceptions: left-handed threads are used on some applications like left-side wheel lug nuts on older cars, opposite-handed pedal threads on bicycles, gas tank caps, propane fittings, to prevent loosening from rotation.

Tool function distinctions matter: using pliers to turn nuts and bolts damages the corners of the fastener (causing rounding/stripping). Use the right tool for the job. PLIERS types: SLIP-JOINT PLIERS have adjustable opening with two positions for general grip, holding nails, light-duty bending; the basic hardware-store pair. NEEDLE-NOSE PLIERS have long thin tapered jaws for reaching into tight spaces, manipulating small parts, bending wire. DIAGONAL CUTTERS (dikes, side cutters) are for cutting wire and small pins. LINEMAN PLIERS have large square nose for cutting near the joint and gripping flat surfaces for pulling/twisting wire; electrical work standard. TONGUE-AND-GROOVE or CHANNEL-LOCK PLIERS have multiple width adjustments; great for plumbing and large fasteners. LOCKING PLIERS or VISE-GRIPS clamp onto workpiece and lock; substitute for vise in field work. CRIMPING PLIERS are for crimping electrical terminals. WIRE STRIPPERS are for removing insulation from electrical wire. WRENCHES: OPEN-END WRENCH has U-shaped opening on each end sized for specific fastener; slips on and off easily but only contacts two of six flats (corners can round). BOX-END (closed-end) WRENCH fully encloses fastener with 6 or 12 points; better grip on six flats. COMBINATION WRENCH has open end one side and box end other (same size); most useful general design. ADJUSTABLE WRENCH (Crescent) has sliding jaw; one wrench fits many sizes; less secure than fitted wrench; can slip and round fasteners under high torque. PIPE WRENCH (Stillson) is toothed and adjustable; bites into round pipe surfaces; for plumbing; damages finished or hex fasteners. SOCKET WRENCH with socket and ratchet is most efficient; socket fully encloses bolt; ratchet allows rapid back-and-forth turning. TORQUE WRENCH measures applied torque; click-type clicks at preset value, beam-type shows pointer on scale; essential for engine bolts, wheel lug nuts, critical fasteners. ALLEN or HEX KEYS are L-shaped or T-handled for hex socket screws. PROPER WRENCH USE: pull toward you whenever possible (safer if wrench slips); always seat fully before applying force; choose size to match exactly; use fitted wrenches for high torque, adjustable for accessibility; on rusted fasteners use penetrating oil first. Metric sizes (mm): 8, 10, 12, 13, 14, 15, 17, 19, 22, 24 common. SAE fractional inches: 7/16, 1/2, 9/16, 5/8, 3/4, 13/16, 7/8 common.

Router: woodworking power tool that uses a high-speed spinning bit to cut, shape, and profile materials. Operation: motor spins bit at 10,000-30,000 RPM; multiple bit shapes create different profiles; can be handheld (with both hands on side handles) or mounted upside-down in a router table (bit projects upward through a hole, workpiece slides over surface). Functions: EDGE PROFILING for decorative shapes like round-over, ogee, cove, bead, chamfer on furniture edges; DADO or GROOVE channels in wood for joinery (shelves into bookcase sides, drawer bottoms); RABBET (step cut along an edge); MORTISE (square holes for joinery); HOLLOW OUT areas like sign letters, trays; FLUSH TRIM (trim laminate or veneer flush with substrate using flush-trim bit, bearing rides on substrate, cutter trims overhang); TEMPLATE WORK where bit follows a template edge to reproduce shapes; JOINERY (dovetail jigs with router create precision dovetails, box joints, locking joints). Router bits come in hundreds of profiles; carbide-tipped for durability; shank sizes 1/4 inch or 1/2 inch (1/2 inch for larger bits and better stability); BEARING on bottom guides cuts along template edges; HEIGHT adjustment of router controls depth. Router types: FIXED-BASE (set depth, plunge into work); PLUNGE ROUTER (spring-loaded, can plunge into middle of a workpiece); COMPACT or TRIM ROUTER (palm router, small one-handed); ROUTER TABLE (large stationary setup with router mounted upside-down). SAFETY: eye and hearing protection (loud); push wood AGAINST rotation of bit (climb-cutting can grab and pull workpiece, light cuts only); take multiple shallow passes for deep cuts; use push pads or push sticks for narrow stock; clamp work or use fence; never adjust running router; unplug to change bits; long sleeves and loose clothing are HAZARDS because they can wrap around bit; check bits for damage before use. OTHER POWER WOODWORKING TOOLS: CIRCULAR SAW (handheld circular blade for straight cuts in lumber and plywood); MITER SAW or CHOP SAW (for angled cross-cuts; sliding compound miter saw most versatile); TABLE SAW (workhorse of woodworking shop for rip cuts, crosscuts, dadoes); JIGSAW or SABER SAW (handheld reciprocating blade for curves); SCROLL SAW (fine curves and inside cuts); BAND SAW (continuous loop blade for curves and resawing); JOINTER (flattens one face and squares one edge); PLANER or thicknesser (uniform thickness); DRILL PRESS (vertical drill for precise holes); SANDERS (random orbit, belt, drum, spindle).

KERF is the slot left by a saw blade, equal to the blade thickness (typically 1/16 inch to 1/8 inch for circular saw blades). Material is removed; you must account for it. STANDARD PRACTICE: position the blade so it cuts on the WASTE SIDE of your marked line, meaning the kerf is removed from the part you don't want, and the line itself remains on the piece you're keeping. This produces an accurate final piece. POWERED SAW BLADE has teeth wider than the blade body (called the SET) to prevent binding. CIRCULAR SAW USE: measure twice, cut once is the old carpentry maxim; mark cut line clearly with pencil or knife; use a straightedge or guide or rip fence for accurate straight cuts; set BLADE DEPTH only slightly deeper than material (less binding, less danger, less splintering of underside); use sharp blade with appropriate TPI for material; plywood is best cut with fine-tooth blade (40-60 teeth, no tear-out) and from the GOOD side DOWN (blade cuts up through bottom, tear-out on top is invisible side); support both sides of cut (workpiece should fall away cleanly, not pinch the blade — pinched blade causes KICKBACK where saw violently flies back at operator); use saw horses with proper support; wait for blade to reach full speed before cutting; allow blade to STOP before lifting saw away. KICKBACK CAUSES: blade pinching in cut (warped wood, unsupported offcut); blade striking foreign object; binding in dense material; dull blade; cutting curves. AVOID kickback by proper workpiece support, sharp blades, correct blade type, never standing in line with possible kickback path. PPE: eye protection (safety glasses or face shield); hearing protection (saws are loud, 100+ dB); dust mask especially for plywood/MDF (formaldehyde and silica); no loose clothing or jewelry; gloves NOT recommended for spinning tools because they can be grabbed. MEASURING AND CUTTING: tape measure marks length; square marks perpendicular cut lines; for angled cuts use a protractor or combination square; laser guides on modern saws help align cuts. RIPPING (cut parallel to grain) vs CROSS-CUTTING (cut across grain): different blade types optimal; combination blades are general-purpose. CIRCULAR SAW SIZE: 7-1/4 inch most common for general carpentry; can cut up to about 2-1/2 inches deep at 90 degrees; cordless options widely available; corded provides more power for heavy work. WORM-DRIVE saws have more torque; SIDEWINDER (standard) saws are lighter, faster blade speed.

Screw types and characteristics: WOOD SCREWS have tapered point; threads typically only on part of shank (smooth shank near head); coarse threads cut their own path in wood; for connecting wood pieces; HEAD TYPES: flat (for countersinking), oval, round, pan; slot, Phillips, square (Robertson), star (Torx) drives; sizes by gauge (#4 small to #14 large) and length (1/2 inch to 4 inches typical). MACHINE SCREWS have uniform threads along entire shank; flat tip (or near-flat); designed to fit into a nut or pre-threaded hole; precise thread fit; used in machinery, electronics, fixtures; head types include pan, round, flat, oval, hex (cap), fillister, button; sizes by diameter and threads-per-inch (e.g., #6-32 = #6 gauge, 32 TPI) or metric (M3, M4, M5, M6, M8, M10 = diameter in mm). SHEET METAL SCREWS are like wood screws but designed for thin metal; threads cut into metal; self-drilling types have drill-point tip eliminating need for pilot hole. DECK SCREWS are wood screws specifically for deck construction; corrosion-resistant coating (galvanized, ceramic-coated, stainless); often square or torx drive for power-driver use. DRYWALL SCREWS have bugle-head for flush installation; coarse-thread for wood studs, fine-thread for metal studs; black phosphate coating; brittle (don't use as structural fasteners). LAG SCREWS or LAG BOLTS are large heavy-duty wood screws with hex heads; for heavy applications like deck framing, attaching beams; predrill pilot hole; install with wrench or socket. SELF-TAPPING SCREWS cut their own threads in metal; not as strong as machine screws in tapped holes but faster installation. CONCRETE SCREWS (Tapcon) are for screwing into concrete after drilling pilot hole; blue-coated typically. THREAD DESIGNATIONS SAE: #6-32, #8-32, #10-24, #10-32, 1/4-20, 1/4-28, 5/16-18, 3/8-16, 1/2-13; the second number is TPI. METRIC: M3-0.5, M4-0.7, M5-0.8, M6-1.0, M8-1.25, M10-1.5; the second number is thread pitch (mm between threads). PILOT HOLES for wood are typically 70-80 percent of screw root diameter; CLEARANCE HOLE in top piece (larger, equal to screw shank) lets it pass through cleanly while threads bite into bottom piece; COUNTERSINK to recess head flush. WASHERS distribute load, prevent damage to material; flat washers for general use; lock washers (split-ring, star, etc.) prevent loosening from vibration; fender washers are large-diameter for soft materials. BOLT vs SCREW distinction: bolts are used with nuts; screws thread into the material itself. NUTS: hex (most common), castle (with slots for cotter pin), lock nut (nyloc has nylon insert, jam nut, all-metal locking), wing nut (finger-tightened). NAIL TYPES: common (full-diameter, for framing), box (thinner, for finish), finish (small head, for trim), casing, brads (very small), roofing (wide head), masonry (hardened). Nail sizes by 'd' (penny): 8d = 2-1/2 inch common framing; 16d = 3-1/2 inch common framing.

Imperial measuring system on tape measures and rulers subdivides each inch into halves, quarters, eighths, sixteenths (and sometimes 32nds and 64ths on precision rules). From largest to smallest tick: WHOLE INCH (labeled with numbers, largest line); 1/2 INCH (second-largest line, midway between inches, often unlabeled); 1/4 INCH (third-largest, at 1/4 and 3/4 positions); 1/8 INCH (fourth-largest, eight equal parts); 1/16 INCH (smallest typical line, sixteen equal parts in one inch). Precision tapes/rules add 1/32 and 1/64 marks. Reading a measurement: two and three-eighths equals 2 plus 3/8 equals 2 and 3/8 inches (written as 2-3/8 inches or 2.375 inches). Common conversions: 1/16 inch equals 0.0625; 1/8 inch equals 0.125; 1/4 inch equals 0.25; 3/8 inch equals 0.375; 1/2 inch equals 0.5; 5/8 inch equals 0.625; 3/4 inch equals 0.75; 7/8 inch equals 0.875. For reading inches: identify whole inches first, then count fractional ticks. TAPE FEATURES: hook at end SLIDES (intentionally) by exactly the thickness of the hook itself; this allows accurate INSIDE measurements (push tape in, hook compresses against object); OUTSIDE measurements (hook over edge, hook pulls out, accurate); hook is riveted loose, not broken. RED NUMBERS every 16 inches mark common stud spacing in US construction. Black or red triangle every 19.2 inches mark another common joist/truss spacing. 1 inch or 1/2 inch indicator on the blade body: when the start of the tape is hard to position, measure from the 1 inch mark and subtract 1 inch from the reading. BLADE WIDTH AND STIFFNESS: wider, stiffer blades extend longer unsupported (blade standout). Lock button keeps blade extended. Belt clip. METRIC TAPES are marked in mm, cm, and meters. 1 meter equals 100 cm equals 1000 mm. Conversions imperial to metric: 1 inch equals 25.4 mm; 1 foot equals 304.8 mm equals 30.48 cm; 1 yard equals 0.9144 m. MEASURING TOOLS hierarchy: TAPE MEASURE (flexible, for general/large measurements); FOLDING RULE (CARPENTER RULE, rigid wooden sections that fold); STEEL RULE or METAL RULER (rigid, precise); COMBINATION SQUARE (adjustable rule with sliding head for 90 and 45 degree measurements); FRAMING SQUARE (large L-shaped for laying out stairs, rafters); SPEED SQUARE (triangular tool for 90 and 45 degree cuts on lumber); PROTRACTOR (measures angles); BEVEL GAUGE (duplicates angles); CALIPERS (precise inside/outside/depth measurements, digital, dial, vernier types, measures to 0.001 inch or 0.01 mm typically); MICROMETERS (most precise common shop tool, 0.0001 inch possible); FEELER GAUGE (thin metal strips of known thickness for measuring gaps like spark plug gap, valve clearance); STUD FINDER (locates wood studs behind drywall); LASER MEASURE (accurate up to 100 plus feet). Carpentry maxim: measure twice, cut once.

Combination square: versatile measuring and marking tool with multiple functions. Components: STEEL RULE (typically 12 inches with inch markings); STANDARD HEAD with 90 degree edge and 45 degree edge that clamps to rule at any position; SOMETIMES includes built-in level vial; SOMETIMES includes a scribe (small pointed marker); optional accessory: center finder head (for finding center of round stock), protractor head (any angle). Functions: mark 90 degree (perpendicular) lines for cross-cuts by placing head against edge and marking along rule; mark 45 degree lines for miter cuts (45 degree face on head works similarly); measure depths (extend rule into recess, head sits on surface); measure heights or clearances; set depth of saw blades or router bits; use level vial to check level/plumb; find center of round stock with center finder; check inside corners are square; establish lines parallel to an edge at consistent distance. PROPER USE: ensure rule is clean and head clamps tight; reference edges of head against work edge; mark with sharp pencil or knife along rule edge. Quality: a good steel combination square (Starrett brand is standard) is reasonably priced and lasts for life. Test a new square: mark a perpendicular line against a known-straight edge, then flip the square over and mark another line from same point; if they don't overlap, the square is off. OTHER MEASURING/LAYOUT TOOLS: SPEED SQUARE (Swanson) is triangular tool to quickly mark 90 and 45 degree lines and lay out rafter angles using roof pitch scale; common in framing. FRAMING SQUARE is L-shaped large square (16 inch by 24 inch) used to lay out stairs, rafter cuts, large layouts; tongue and blade; tables stamped on it for stair stringers and rafter cuts. MITER GAUGE slides in table-saw slot and holds workpiece at angles for crosscuts. MITER BOX has slot guides for hand-sawing accurate angles. MARKING GAUGE has single pin that scribes lines parallel to edge at set distance; common in joinery. PROTRACTOR measures any angle in degrees. BEVEL GAUGE or SLIDING T-BEVEL has sliding blade that locks at any angle; transfer angles from one place to another. SQUARE-AND-COMPASS for geometric layout. DIVIDERS measure or transfer equal distances. LAYOUT FOR CARPENTRY: establish reference faces/edges (marked, used as reference for measurements); don't measure from edges that have been cut from rough lumber — use jointed/cut reference faces; mark all cuts before cutting and verify; for repeated cuts of same length use a stop block on saw fence; for 90 degree crosscuts in repetitive work use miter saw (chop saw) with fence; dog-ear symbols (cross marks) indicate the waste side of a cut line. PLUMB AND LEVEL: plumb is vertical (perpendicular to gravity); level is horizontal. Tools: level (bubble vial; sometimes called spirit level from old times when filled with alcohol); plumb bob (weighted line for vertical); laser level (modern; projects level or plumb lines). Digital levels show angles numerically.

Shop safety is paramount — most shop injuries are preventable. Core safety principles: EYE PROTECTION at all times (safety glasses or goggles; full face shield for grinding or splash hazards); standard sight cannot be replaced if damaged; even momentary eye protection failure can permanently injure (lawnmower blade hits a rock could send a projectile into eye; angle grinder disk shatters into high-speed shrapnel; saw kicks back chip as flying debris). HEARING PROTECTION (table saws, routers, planers, vacuum cleaners exceed 90 dB; prolonged exposure causes permanent hearing loss; foam plugs or earmuffs or both for very loud). RESPIRATORY PROTECTION (dust masks N95 minimum for general dust; respirators for chemicals, treated lumber, MDF/particle board with formaldehyde, spray paint, lacquer; silica dust from cutting masonry, concrete, certain woods causes silicosis). APPROPRIATE CLOTHING (close-fitting; no loose sleeves, dangling cords, ties, jewelry, long hair tied back; they can get caught in spinning parts; sturdy closed-toe shoes). GLOVES for handling rough materials, sharp edges, chemicals; but NEVER WEAR GLOVES with spinning tools (drill press, lathe, table saw, router) because gloves can catch and pull hand into the tool. Hair control: long hair tied back. WORKING SAFELY: read instruction MANUAL for any new tool before use; understand controls, capabilities, limits; NEVER REMOVE safety guards or defeat safety features because they exist due to past injuries; ONE TASK AT A TIME (don't multitask with power tools; full attention required); UNDISTRACTED workspace (clean area, proper lighting, no obstructions); children and pets out of shop; NEVER OPERATE while impaired (alcohol, drugs including some prescriptions, severe fatigue, illness); BE PREPARED for emergencies (first aid kit accessible, fire extinguisher of ABC type, phone for 911, know where breakers are). ELECTRICAL SAFETY: GFCI outlets in shops and outdoors; check cords for damage; don't use power tools in wet conditions; UNPLUG when changing blades, bits, accessories; don't overload circuits; use heavy-duty extension cords; grounded tools (3-prong) for safety unless double-insulated. FIRE SAFETY: combustible materials away from heat sources; saw dust accumulates and should be cleaned regularly; SOLVENT-SOAKED RAGS can spontaneously combust so store in metal containers; welding/grinding sparks fly far so clear area and have fire watch; spray painting and finishing produce flammable vapors needing good ventilation. CHEMICAL SAFETY: read SDS (Safety Data Sheets); ventilation for fumes; skin protection for solvents and adhesives; eye protection from splashes. ERGONOMICS: lift with legs not back; don't lift more than safe; stretch and rest during long sessions. KNOW HOW TO STOP each tool quickly (foot pedal release, panic button, etc.); know first aid for cuts (direct pressure, elevation, call 911 for severe); have current tetanus shot.