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. We 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 the most frequently used tools in auto repair scenarios, suitable for basic operations such as bolt disassembly, part clamping, metal trimming, etc., with the characteristics of strong portability and flexible operation. The core tools and functions are as follows:

Pliers: the core tool used in auto repair to disassemble/install bolts and nuts. It is subdivided according to the shape of bolts and operation requirements:

Open wrench: commonly known as "dumb wrench", the head is an open clasp, suitable for open space and no need to completely wrap the bolt, can be quickly inserted into the bolt, but the edge fit is low, easy to slip, suitable for initial loosening or standard hex bolts.

Plum Blossom wrench: The head is a closed plum blossom-shaped clamping jaw that fits tightly with the hexagonal surface of the bolt, effectively preventing slippage and damaging the bolt. It is suitable for high-precision disassembly or scenarios with limited space where stable force application is required. Typically comes as a set (covering common specifications from 6mm to 32mm).

Ratchet wrench: It can be used with different specifications of sockets. With built-in ratchet structure, it can achieve "one-way force and reverse rotation", which can not be repeatedly disassembled, greatly improving the disassembly efficiency of dense bolts (such as engine cylinder head).

Pliers tool: a core accessory used with wrench tools. It is an essential part of auto repair because it can completely wrap the bolt head and adapt to complex working conditions. Its classification and characteristics are as follows:

Core Structure and Specifications: The sleeve features a short tubular design. One end contains a hexagonal or dodecagonal socket for bolt engagement, while the other end has a square-head hole that mates with the handle's square tenon. Available in three series (6.3mm/1/4 inch, 10mm/3/8 inch, 12.5mm/1/2 inch) based on tenon width, these components are specifically designed for small precision bolts, standard chassis bolts, and high-torque engine bolts applications.

Common types and uses:

Standard sleeves come in two types: hexagonal and twelve-sided. The hexagonal sleeve provides a larger contact area with bolts, making it ideal for high-strength disassembly. The twelve-sided sleeve features a contact angle every 30 degrees, allowing quick installation in tight spaces, though it's not recommended for high-torque or wear-prone bolts.

Extended sleeve: the length is more than three times that of the standard type, also known as "deep sleeve", with bolt release hole, suitable for recess or long screw on the bolt (such as gearbox oil pan bolt).

Special-purpose sleeves: These include spark plug sleeves (featuring built-in rubber seals for secure attachment), pneumatic impact sleeves (thick-walled design compatible with pneumatic wrenches), spline sleeves (matching the threaded splines on intake manifolds), and thin hub sleeves (designed for tight spaces in wheel rims).

Precautions: Strictly match the metric/English specifications of bolts to avoid damage caused by dimensional deviations; Clean debris inside the sleeve before use to prevent slipping and injury; Do not connect two or more sleeves in series to avoid fracture due to unstable force.

Screwdriver: designed for different slot screws, the core function is to tighten / loosen screws:

Straight screwdriver: The head is flat, and it is suitable for straight "straight" screws. It is commonly used in chassis parts or simple plastic parts of old models.

Cross screwdriver: The head is "cross" shaped, suitable for cross-groove screws. It can be used more evenly and not slip easily. It is widely used in body interior, engine accessories and other parts. Note that the corresponding model (such as PH2, PH3) should be matched according to the screw specification.

Clamp class: with "clamping, cutting and bending" as the core function, subdivided according to operation requirements:

Nail clamps: Long and pointed head, suitable for narrow space (such as wire harness joints, small size springs), can accurately hold small parts, some with shear blade, can also cut thin wires.

Skew pliers: The head is a slanted shear blade, mainly used to cut wires, straps or fine metal wires, strong cutting force, not suitable for clamping parts, avoid damage to the edge.

Carpenter's pliers: The head is wide and the jaws can be adjusted, which can be used to hold water pipes, oil pipes or slightly correct deformed metal parts (such as chassis brackets), but can not be used for high strength disassembly.

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.