¶ Screwdrivers, Pliers, and Wrenches
Screwdrivers, pliers, and wrenches are manual tools used for fastening, gripping, and turning threaded fasteners. Together they form the core of any mechanic's or carpenter's toolkit.
Screwdrivers are tools for turning screws, consisting of a handle, shaft, and tip that mates with the screw head.
- Flathead (slotted) — Simple straight slot; available in tip widths from 2–12 mm. The tip should match the slot width for proper engagement.
- Phillips — Cross-shaped recess with tapered sides; sizes #0 (small) through #3 (large). The tapered design causes the driver to cam out (slip out) under high torque to prevent over-tightening.
- Robertson (square) — Square recess; sizes #0 to #4. The square drive provides excellent torque transfer without cam-out. Common in Canadian and marine construction.
- Torx (star) — Six-point star-shaped recess; sizes T6 through T60. Excellent torque transfer with minimal cam-out. Common in automotive and electronics.
- Hex (Allen) — Hexagonal recess; metric sizes 1.5–10 mm, imperial sizes 1/16–3/8 in. Used in furniture assembly, machinery, and bicycles.
¶ Sizes and Styles
- Cabinet screwdrivers — Slim shaft, round handle, used for cabinet hardware
- Heavy-duty screwdrivers — Thick shaft, square or fluted handle, for high-torque applications
- Precision screwdrivers — Small tips for electronics and fine work, often with a swivel cap
- Insulated screwdrivers — Rated for electrical work (typically 1000V)
¶ Handle Materials
Handles are made from wood (traditional), plastic (polypropylene, nylon), or rubber-over-molded plastic (for grip). Square or hexagonal handle cross-sections provide better grip for high torque.
Quality screwdriver tips are made from hardened tool steel (S2, 8650, or CR-V). Tips should be precisely ground to fit the screw recess for maximum torque transfer and minimal damage to the screw head.
Pliers are gripping tools with two opposed jaws pivoted near the center.
- Slip-joint pliers — 15–20 cm (6–8 in); adjustable pivot allows two jaw positions for different sizes
- Linesman's pliers — 18–20 cm (7–8 in); combination gripping, cutting, and crimping. The flat jaw profile allows twisting wire and gripping flat objects.
- Needle-nose pliers — 15 cm (6 in); long, tapering jaws for reaching into tight spaces
- Tongue-and-groove pliers (Channellock) — 25–40 cm (10–16 in); adjustable multi-position pivot for gripping pipes and large objects
- Locking pliers (Vise-Grip) — 15–25 cm (6–10 in); cam-action mechanism locks the jaws at a preset tension
¶ Cutting and Gripping Features
High-quality pliers feature forged steel construction (typically CR-V or 6150 steel). Serrated jaws provide secure grip on round or slippery objects. Cutting edges (wire cutters) are located near the pivot for maximum mechanical advantage. Insulated handles are rated for electrical work.
Wrenches are tools for applying torque to bolts, nuts, and other threaded fasteners.
- Combination wrench — Open-end on one side, box-end on the other; sizes 8–22 mm (metric) or 5/16–1 in (imperial)
- Adjustable wrench — 15–30 cm (6–12 in); adjustable jaw for variable sizes
- Socket set — 1/4-inch drive (light duty), 3/8-inch drive (general automotive), 1/2-inch drive (heavy duty). Includes ratchet handle, extensions, and universal joints.
- Hex key set — L-shaped or T-handle; metric and imperial sizes
- Open-end — Fits over a fastener from the side; faster to use but can round off corners
- Box-end — Encloses the fastener completely; 6-point (hex) grips the faces of the fastener for maximum torque, 12-point allows finer indexing but can round corners
Quality wrenches are made from forged chromium-vanadium (CR-V) or chromium-molybdenum (CR-MO) steel. Surface treatment may be chrome-plated (corrosion resistant, hard) or black oxide (non-reflective, oil-holding). Markings indicate size and material.
- The Complete Guide to Tools (Chatfield, 2005)
- Tools and Their Uses (U.S. Navy, 1971 / Dover reprint)
- Graves, H. (2016). The Toolbox Book. Taunton Press.