Automotive repair is a meticulous field that integrates technical expertise with hands-on practice. The realization of precise diagnostics and efficient repairs relies not only on technicians' professional knowledge but also on their proficiency in using various maintenance tools. Automotive repair tools are diverse and functionally specialized, ranging from basic manual tools to intelligent electric equipment, and even high-pressure tools dedicated to new energy vehicles. Each category corresponds to specific repair scenarios. For automotive repair professionals, systematically mastering tool classifications, names, and usage essentials is the core prerequisite for improving repair efficiency and ensuring operational safety. Changkun will comprehensively organize the system of automotive repair tools, detail their functional characteristics, and address common questions to provide clear reference materials for practitioners.

I. Core classification and functional analysis of auto repair tools

According to the use and drive mode, auto repair tools can be divided into four categories: general manual tools, professional maintenance tools, electric and pneumatic tools, and new energy vehicle special tools. Each type of tool has its irreplaceable application scenarios. The specific classification and functions are as follows:

(1) General manual tools: "basic equipment" for maintenance operations

General manual tools are widely used in auto repair for tasks like bolt disassembly, part clamping, and metal trimming. They are portable, flexible, and essential for basic operations.

1. Pliers

• Core tool for bolt and nut installation/disassembly.

• Adaptable to various bolt shapes and operational needs.

2. Open Wrench (“Dumb Wrench”)

• Open-head design, quick to insert in open spaces.

• Suitable for initial loosening or standard hex bolts.

• Lower fit accuracy, prone to slipping.

3. Plum Blossom Wrench

• Closed, plum-blossom-shaped head that fits bolt hexagon tightly.

• Prevents slippage and bolt damage.

• Ideal for high-precision disassembly or confined spaces.

• Typically comes in sets (6–32 mm).

4. Ratchet Wrench

• Works with various socket sizes.

• Built-in ratchet allows one-way force with reverse rotation.

• Improves efficiency for dense bolts (e.g., engine cylinder heads).

5. Pliers Accessories

• Complements wrenches to fully grip bolt heads.

• Features short tubular sleeves: one end with hex/dodecagonal socket, other with square-head hole for handle tenon.

• Available in three series: 6.3 mm (1/4”), 10 mm (3/8”), 12.5 mm (1/2”), covering small precision bolts, chassis bolts, and high-torque engine bolts.

Common types and uses:

• Standard Sockets

• Hex Socket: Larger contact area with bolts, suitable for high-torque applications and heavy-duty disassembly.

• 12-Point Socket: Provides a contact angle every 30°, allowing faster engagement in confined spaces. Best for quick installation but not recommended for high torque or worn bolts.

• Deep Sockets

• More than three times longer than standard sockets.

• Also called deep sockets.

• Designed with a bolt-release hole, ideal for recessed fasteners and long bolts (e.g., gearbox oil pan bolts).

• Special-Purpose Sockets

• Spark Plug Socket: Built-in rubber insert for secure spark plug retention.

• Impact Socket: Thick-walled design for use with pneumatic impact wrenches.

• Spline Socket: Matches spline fasteners commonly found on intake manifolds.

• Thin-Wall Wheel Socket: Designed for tight wheel-rim spaces.

• Safety Precautions

• Match metric and imperial socket sizes correctly to prevent damage.

• Remove debris from inside the socket before use to avoid slipping.

• Never connect multiple sockets in series, as this may cause breakage due to unstable force.

Screwdrivers

• Flathead Screwdriver

• Flat blade tip for slotted screws.

• Commonly used on older vehicle components and simple plastic parts.

• Phillips Screwdriver

• Cross-shaped tip for Phillips screws.

• Provides better grip and reduced slipping.

• Widely used for interior trim, engine accessories, and body components.

• Select the correct size (e.g., PH2, PH3) to match the screw specification.

Pliers

• Needle-Nose Pliers

• Long, narrow jaws for confined spaces.

• Ideal for handling wire connectors, small springs, and delicate components.

• Some models include cutting edges for thin wires.

• Diagonal Cutting Pliers

• Angled cutting jaws designed for cutting wires, cable ties, and thin metal wire.

• High cutting efficiency but not suitable for gripping parts.

• Slip-Joint Pliers

• Wide jaws with adjustable opening.

• Suitable for gripping pipes, hoses, and lightly reshaping metal parts such as brackets.

• Not intended for high-force disassembly tasks.

Other basic tools:

Hammer Types: Three categories include wooden, rubber, and iron hammers. Wooden/rubber hammers are soft to avoid dents on fragile parts like plastic trim panels or aluminum alloy components. Hard iron hammers, with their high hardness, are reserved for striking heavy-duty parts such as metal brackets and bolts. These require spacer blocks to prevent part deformation.

File: the surface is equipped with dense file teeth, used to trim burrs and flash of metal parts (such as welded joints, fracture surfaces of parts), which can be divided into flat file, round file and triangle file according to shape, suitable for different shapes of part surfaces.

Torque wrench: Though classified as a "precision tool", it is commonly used alongside general-purpose tools to secure bolts requiring torque control (e.g., tire bolts, engine crankshaft bolts). It allows setting torque values and triggers a "click" sound when tightened to the preset level, preventing bolt breakage from excessive tightness or leakage from loose connections.

(2) Professional maintenance tools: targeted to solve specific scenario requirements

Professional tools are special equipment designed for specific automotive systems (such as engine, chassis, electrical system), with highly focused functions. They are the "key equipment" to solve complex maintenance problems. The core tools and functions are as follows:

Engine system special tools:

Spark plug wrench: Available in socket and wrench types. The socket type accommodates various spark plug specifications (e.g., 16mm, 21mm), featuring a built-in rubber ring that securely "adheres" to the plug during removal to prevent dropping. The wrench type is designed for tight spaces around spark plug holes, ensuring safe disassembly without damaging the porcelain body.

Valve wrench: used for the disassembly and installation of engine valves. It is divided into "valve spring compressor" and "valve clamp": the former can compress the valve spring to facilitate the removal of the valve retaining ring; the latter is used to hold the valve to avoid the valve tilting during installation.

Timing Tool Kit: Engine timing system designed with precision, including timing belt/chain alignment pins, camshaft mounting tools, and crankshaft mounting tools. This kit ensures accurate positioning of the camshaft and crankshaft during timing belt/chain replacement, preventing cylinder head misalignment caused by timing errors.

Chassis and tire tools:

Tire wrench: Available in two types-cross-type and lever-type. The cross-type features a hex socket that fits tire bolts, with an extended handle for enhanced leverage. The lever-type utilizes the principle of leverage to reduce force application, making it ideal for manual tire bolt removal. Note: Always match the wrench size (e.g., 19mm or 21mm) with the bolt specification.

Jacks: Vehicles are lifted using jacks, which come in two types: mechanical (spiral jack) and hydraulic (horizontal jack). Mechanical jacks have lower load capacity and are portable, making them ideal for temporary tire replacements. Hydraulic jacks provide stronger support (typically 2-5 tons) with smooth lifting motions, widely used in chassis maintenance tasks like brake pad replacements and suspension component repairs. When using them, ensure they are properly positioned at the vehicle's designated jack support points to prevent damaging the body structure.

Special tools for electrical systems:

Multimeter: although it is not a "mechanical tool", it is the core of electrical maintenance. It can measure voltage (such as battery voltage, sensor signal voltage), current (such as line current), resistance (such as wire harness on/off, sensor resistance), and is used to diagnose problems such as battery charge, sensor fault, line short circuit, etc.

Car diagnostic instrument: Connect the vehicle OBD interface, read the fault codes of the engine, gearbox, ABS and other systems, view the data flow in real time (such as engine speed, water temperature, fuel injection pulse width), is the "essential tool" for modern automotive electronic fault diagnosis.

(3) Electric and Pneumatic Tools: "Power Equipment" to improve efficient maintenance

Electric and pneumatic tools are powered by "electric energy and compressed air". Compared with manual tools, they have the advantages of "less effort and high efficiency" and are suitable for high intensity and large workload maintenance scenarios:

Power tool: 

Drill: A combination of different drill bits (twisted drill, impact drill) used to drill holes in metal and plastic parts (e.g., mounting brackets, fixing harnesses). Some drills with "impact function" can be used to lightly chisel concrete (e.g., body hole fixing accessories).

Electric wrench: divided into charging type and wired type, used with a socket. It has high torque and fast rotation speed. It is mainly used for disassembly/installation of large torque bolts (such as tire bolt, drive shaft bolt), which greatly reduces the manual force intensity, but it should be noted that the torque should be adjusted to avoid damage caused by over-tightening.

Grinders: These are categorized into vertical grinders and angle grinders. Vertical grinders feature slender heads that can access tight spaces like engine cylinder grooves, ideal for deburring and surface polishing. Angle grinders, with higher power output, are used for large-area metal work such as rusted chassis sections and welded joints. They require protective face shields to prevent metal debris from flying.

Electric welding machine: divided into arc welding and argon arc welding, used for welding metal parts (such as broken chassis brackets, exhaust pipes), arc welding is suitable for ordinary steel, argon arc welding is suitable for stainless steel, aluminum alloy and other corrosion-resistant materials, operation should be certified to avoid the risk of electric shock or fire.

Air tool:

Pneumatic wrench: powered by compressed air, with greater torque and faster rotation speed than electric wrench. It is suitable for high-intensity operations in professional maintenance plants (such as heavy truck tires, large engine bolts), which should be used with pneumatic impact sleeve instead of manual sleeve.

Air grinding wheel: used for rapid grinding of metal surfaces (such as rust removal before body scratch repair, planar grinding of engine cylinder head), high grinding efficiency, and not easy to damage parts due to overheating, suitable for batch maintenance operations.

(IV) Special tools for new energy vehicles: "exclusive equipment" for high pressure safety and battery maintenance

New energy vehicles contain high-voltage electric system (above 300V) and power battery pack, which require special tools to ensure the safety and accuracy of maintenance. The core tools and functions are as follows:

High pressure safety detection tools:

Megohmmeter: Also known as insulation resistance meter, used to detect the insulation resistance of high-voltage cables, motor controllers, power batteries and other components to ensure that their insulation performance to the body meets safety standards (usually required to be ≥500Ω/V), is a must-test tool before high-voltage operation.

High voltage safety tester: can simulate high voltage leakage scene, test the response performance of vehicle high voltage protection system, and measure the voltage rating of insulation tools to ensure that the tools meet the requirements of high voltage operation above 1000V.

CATIII class multimeter: Compared with traditional multimeter, it has higher voltage tolerance (≥600V), and can safely measure the AC/DC voltage, current and resistance of high-voltage system. It is suitable for diagnosing battery cell voltage, charging pile interface fault and other scenarios.

Clamp meter: can measure the large alternating current in the drive motor wire without cutting off the line, and is used to diagnose motor load abnormalities, line short circuit and other problems.

High pressure system disassembly tool:

Insulated manual tool set: includes insulated handle wrench, screwdriver, needle-nose pliers, etc., the handle voltage rating is more than 1000V, the surface is insulated, used to remove high-voltage terminal posts, battery bolts and other components, to avoid the risk of electric shock.

Insulated torque wrench: with torque setting function and insulated handle, used to tighten bolts of high pressure components (such as battery module fixing bolt), which ensures torque accuracy and prevents electric shock during operation.

Battery maintenance tools:

Battery lift platform vehicle: the load can reach 2-3 tons, and the height and Angle can be adjusted accurately. It is used to safely disassemble and assemble the power battery pack from the bottom of the vehicle, so as to avoid battery collision damage caused by manual handling.

Battery module maintenance instrument: can carry out voltage balancing and SOC calibration for single modules in power battery group, solve problems such as battery capacity attenuation and endurance shrinkage, and prolong battery service life.

Air tightness detector: used to detect the sealing of the battery pack shell, and determine whether there is a leak point through pressurized test, so as to prevent rainwater and dust from entering the battery pack and causing short circuit.

Safety protection equipment:

Including insulated gloves (pressure resistance ≥1000V), insulated shoes, goggles, insulated blankets, etc., where the insulated gloves need to be tested for pressure every 6 months; dry powder fire extinguishers should also be provided to deal with the risk of possible battery fire.

II. Answers to common questions about auto repair tools

1. Why are there three types of wrenches: opening, plum blossom and ratchet?

Different types of wrenches are designed to meet the core requirements of "screw positioning space and operational efficiency": The open-end wrench is suitable for open spaces with single-screw specifications, enabling quick operation; the socket wrench is ideal for tight spaces or slippery screws, ensuring better grip; the ratchet wrench targets densely packed bolts (e.g., gearbox housings) by applying "unidirectional force" to reduce tool disassembly frequency. When used in combination with a tool sleeve, these three types of wrenches can cover most screw removal scenarios, preventing inefficiency or part damage caused by unsuitable tools.

2. How to accurately select the appropriate sleeve tool?

When selecting couplings, follow the "three-step matching method": First, determine the coupling series based on bolt torque (choose 6.3mm series for low torque, 12.5mm series for high torque). Second, select the coupling type according to bolt head shape (hexagonal bolts require hexagonal couplings, spline bolts require spline couplings). Finally, choose the length based on installation space (extend couplings for recessed areas, select thin couplings for inner hub surfaces). Note the distinction between metric and imperial units: For example, M12 bolts require 19mm couplings, while 1/2-inch bolts need 13mm couplings to prevent damage from improper size mismatch.

3. Why should screwdriver be distinguished by "type" and "specification"?

Different screwdriver types (flathead, Phillips) are designed to match specific screw grooves: Phillips screws provide more even force distribution and better grip compared to flathead screws, making them more common in modern vehicles; while specifications like PH2 or flathead 6mm require matching —— small-sized screwdrivers to avoid head deformation or groove damage when using larger ones. Conversely, using a small screwdriver for large screws will fail to fully embed them into the groove, resulting in slipping.

4. What are the key points to pay attention to when using insulation tools in new energy vehicle maintenance?

Before use, check whether the insulated handle is damaged or aging, if there are cracks on the surface, replace it immediately;

Insulating tools should be stored separately to avoid mixing with metal tools to cause insulation layer wear;

After each use, it should be wiped clean with a dry cloth. Do not rinse with water or contact with oil to prevent the deterioration of insulation performance;

Regularly send professional organizations to conduct pressure tests to ensure that the insulation level meets safety requirements.

5. What factors should be focused on when choosing auto repair tools?

Applicability: prioritize matching maintenance scenarios (such as choosing timing tools for traditional engine repair, insulation tools for new energy vehicles repair), to avoid "using a big tool for a small use" or "insufficient tools";

Durability: Select high hardness material (such as wrench selected CR-V alloy, screwdriver selected S2 steel, socket selected chromium steel alloy), surface with anti-rust treatment (such as chrome plating, black), extend tool life;

Safety: Electric tools should meet the "3C certification", new energy insulation tools should have voltage rating mark; torque wrench should be calibrated once a year to ensure torque accuracy;

Convenience: The tool kit should be equipped with a classified storage box for easy access and storage; portable tools (such as rechargeable electric wrench) should pay attention to battery life to meet the needs of outdoor rescue.

6. What are the safety precautions that must be taken when using power tools?

Power supply safety: wired power tools should check whether the power cord is broken to avoid leakage; charging tools should use original chargers, do not use different brands of chargers to prevent battery bulge or fire;

Operation specifications: Before use, it is necessary to confirm that the tool switch is in the "off" state, and start away from the body; for high-speed tools such as electric drill and angle grinder, do not touch the rotating parts with your hands to avoid scratches;

Protective measures: wear protective equipment —— wear a protective mask (to prevent metal fragments) when using an electric grinder or angle grinder, and wear welding gloves and goggles when using an electric welder to avoid electric shock or burns;

Equipment maintenance: clean the debris and oil stains on the surface of the tool after use. The electric wrench should be checked regularly whether the socket is loose or not, and the drill should be replaced with worn drill bits to ensure normal use next time.

Automotive tools serve as the "hands and feet" of vehicle maintenance. From basic tools like wrenches and sockets to specialized timing components, from traditional electric equipment to dedicated insulation gear for new energy vehicles (NEVs), each type of tool fulfills specific functional requirements. For auto mechanics, it's crucial not only to memorize tool names and classifications but also to understand the "tool-scenario compatibility" ——. For instance, using a rubber hammer to tap plastic parts, applying torque wrenches to secure high-pressure bolts, or repairing battery systems with insulating tools are essential—not just for boosting efficiency but also for preventing part damage and ensuring operational safety. Particularly in NEV maintenance, tool expertise and safety directly impact repair quality and personnel safety. Only by deeply integrating "tool characteristics" with "maintenance needs" can technicians perform precise operations in complex scenarios, ultimately achieving the goals of "efficient, safe, and high-quality" repairs.