What are the 4 types of jaws?

In emergency rescue, the four types of “Jaws of Life” tools are cutters, spreaders, combination cutter–spreaders, and rams. If you meant “jaws” in anatomy or machining, the term is used differently; we outline those meanings below to clarify how the phrase is used across fields.

The four “Jaws of Life” used in vehicle extrication

Fire and rescue crews use a family of powered hydraulic tools—popularly called the “Jaws of Life”—to free people from wrecked vehicles and collapsed structures. These tools fall into four functional types, each optimized for a particular task on scene.

• Cutters — Scissor-like blades designed to sever vehicle components such as A/B/C pillars, door hinges, roof rails, pedals, and steering columns. Modern cutters are engineered to resist blade separation and are rated for their ability to cleanly cut through high-strength and ultra-high-strength automotive steels.
• Spreaders — Twin, claw-tipped arms that pry apart metal, typically used to pop doors, lift or roll dashboards, and create purchase points for other tools. They can also pull when fitted with chains or attachments.
• Combination tools (combi) — A hybrid tool that both spreads and cuts, useful for first-arriving companies or tight spaces. Combi tools trade some peak cutting or spreading performance for versatility and speed of deployment.
• Rams — Telescoping cylinders that push components apart, commonly used to displace dashboards, move seats, or stabilize and lift structures incrementally. Rams come in various lengths and stroke capacities to match the space available.

Together, these tools allow teams to choose the fastest, safest tactic for disentanglement. Departments typically mix full-performance cutters and spreaders with a combi tool and one or more rams to cover most extrication scenarios.

Power sources, safety, and standards

Rescue tools are powered either by traditional hose-and-pump hydraulics or by battery/electric-hydraulic systems that eliminate hoses for faster deployment and mobility. Performance and safety benchmarks are defined in standards such as NFPA 1936, which classifies tools by cutting, spreading, pulling, and pushing capability and prescribes test methods. Crews train to match tool ratings to modern vehicle materials, including boron and martensitic steels, and to manage hazards like undeployed airbags, high-voltage EV systems, and spring-loaded components.

If you meant anatomy: “jaw” types in biology

In biology, there isn’t a single, universal set of “four types of jaws,” but several common frameworks describe jaw and tooth attachment across species and mouthpart specializations.

• Vertebrates — Broadly divided into jawless (agnathans, e.g., lampreys) and jawed (gnathostomes). Among reptiles and some fishes, tooth attachment to the jaw is categorized as acrodont (tooth on the edge), pleurodont (tooth on the inner side), or thecodont (tooth in a socket, as in mammals and crocodilians).
• Insects — Often grouped by mouthpart function rather than “jaws”: chewing/biting, piercing–sucking, siphoning, and sponging—four classic categories taught in entomology.
• Humans — Two jaws: the mandible (lower) and maxilla (upper). Orthodontics classifies bite relationships (occlusion) into Classes I, II, and III; this is a bite classification, not “jaw types.”
• Functional evolution — Across vertebrates, the jaw joint and musculature vary widely (e.g., mammalian dentary–squamosal joint vs. reptilian quadrate–articular), reflecting diet and evolutionary lineage rather than fitting a neat “four types” model.

So while “four types” maps neatly to insect mouthpart categories, biological usage depends on the taxonomic group and the feature being classified (bones, joints, tooth attachment, or function).

If you meant machining: chuck and vise jaws

In machining and fabrication, “jaws” usually refer to the clamping surfaces on chucks and vises. Shops commonly talk about jaw categories based on material and geometry to suit workholding needs.

• Hard jaws — One-piece or master jaws (often serrated) used for quick, durable clamping of common diameters; ideal for roughing and general work.
• Soft jaws — Machinable jaws bored or milled to match a specific part’s profile for high concentricity and repeatability; essential for second-ops and delicate finishes.
• Pie jaws (segment jaws) — Large, curved soft jaws that provide broad circumferential contact for thin-walled or large-diameter parts, improving roundness and reducing distortion.
• Specialty/step/V-jaws — Application-specific jaws (stepped, V-groove, serrated, magnetic, or elastomer-faced) for gripping irregular shapes, shafts, or to balance clamping force and access.

Selection balances grip security, part protection, and runout requirements. Many shops keep both hard and soft options on hand and machine soft jaws per job to ensure accurate, repeatable holding.

How to tell which “jaws” someone means

Because “jaws” spans rescue, biology, dentistry, and machining, context clues help pin down the intended meaning quickly.

1. Setting: Fire/rescue training or incidents imply “Jaws of Life”; labs or wildlife indicates biology; shop floors point to workholding.
2. Keywords: “Extrication,” “cutter,” “ram” versus “mandible,” “occlusion” versus “chuck,” “vise,” or “soft jaws.”
3. Metrics: kN, cutting ratings, and stroke (rescue) vs. runout and grip torque (machining) vs. anatomical terms (biology/dentistry).
4. Standards: References to NFPA 1936 (rescue) or ISO/ASME workholding specs (machining) are strong signals.

Clarifying the domain ensures you get the correct “four types” rather than a mismatched answer.

Summary

The four types of “Jaws of Life” used in emergency extrication are cutters, spreaders, combination cutter–spreaders, and rams. If you were asking about biology or machining, “jaws” is categorized differently: insects have four classic mouthpart types (chewing, piercing–sucking, siphoning, sponging), while shops speak of hard, soft, pie, and specialty/step/V-jaws for clamping. The right answer hinges on the field you have in mind.

What are the Jaws of Life?

The “Jaws of Life” refers to hydraulic rescue tools used by emergency responders to extricate people from vehicle accidents, named after their powerful ability to cut, spread, and pry apart crushed metal and other debris. Developed by George Hurst in the 1960s, these tools operate using a portable engine that pumps hydraulic fluid into a piston-cylinder, which then powerfully manipulates the tool’s arms or jaws. There are four main types: spreaders, which pry open structures; cutters, for shearing through metal; rams, to push or lift; and combination tools, which perform multiple functions.
 
How They Work

• Hydraulic Power: A pump, often driven by a portable engine, pushes hydraulic fluid to a piston inside the tool. 
• Forceful Action: The movement of the piston activates either cutting blades or spreading arms, generating immense force. 
• Versatility: The system is used to either spread metal apart to create space or cut through it to free victims. 

Types of Tools

• Spreaders: Used to create space by applying outward force to compressed car frames. 
• Cutters: Feature scissor-like attachments for cutting through thick metal and other materials. 
• Rams: These tools apply direct, outward pressure to dislodge or push parts of a vehicle. 
• Combination Tools: A single, compact device that combines cutting and spreading functions. 

Why They Are Important

• Speedy Extrication: The tools allow for faster removal of victims from dangerous situations, significantly improving their chances of survival within the critical “golden hour” after an injury. 
• Enhanced Safety: They reduce the risk of injury to both victims and rescuers by providing a safer and more precise alternative to older methods like blowtorches and saws. 
• Precision: The tools can cut and spread with high precision, crucial for working in close quarters and avoiding damage to the trapped victims. 

What are the 4 types of Jaws of Life?

The four types of Jaws of Life tools are spreaders, cutters, rams, and combination tools, which are all hydraulic rescue tools used to extricate people from accidents and disasters by using powerful hydraulic force. Spreaders pry open structures, cutters slice through metal, rams push heavy objects to create space, and combination tools merge these functions into a single unit.
 
Here’s a breakdown of each type:

• Spreaders: Opens in new tabThese tools are used to pry apart metal and other materials by inserting their arms into narrow gaps and applying outward force. 
• Cutters: Opens in new tabDesigned to cut through metal and other large debris, cutters are effective for removing vehicle doors, roofs, or other obstructed parts. 
• Rams: Opens in new tabRams are used to push heavy objects to create space, such as pushing a dash out of the way to free a trapped person. 
• Combination Tools: Opens in new tabA single tool that combines the functions of a spreader and a cutter, allowing for faster and more efficient rescue operations. 

These tools are powered by a generator that supplies hydraulic force and are essential for firefighters and rescue teams to safely and quickly free victims from vehicles after accidents or from collapsed structures after disasters.

What are the four specifications of Jaws of Life?

Jaws of Life come in four different styles. Three of them function as separate tools while the last works as a combination of the three. Regardless of which tool you have, they are all crucial to the safe removal of trapped victims. The four types are spreaders, cutters, rams and combination.

What are the Jaws of Life actually called?

The tools often called the “Jaws of Life” are technically known as hydraulic rescue tools, with the specific brand name Hurst Rescue Tools also being a correct term, as the term “Jaws of Life” originated from this company’s equipment. This system of tools includes cutters for shearing metal, spreaders for prying open crushed doors and frames, and rams for pushing apart vehicle components. 
Breakdown of the tools:

• Cutters: Opens in new tabA type of hydraulic shear that uses pincers to apply inward pressure and cut through car parts. 
• Spreaders: Opens in new tabThese tools have arms that open and push apart vehicle panels to create an escape route. 
• Rams: Opens in new tabUsed to exert force and create space by extending a piston, often to push a dashboard away from trapped occupants. 

Origin of the name:

• George Hurst, a race car parts manufacturer, developed these tools in 1961 to help free trapped victims from crashed vehicles more quickly. 
• His company’s line of tools became so well-known that “Jaws of Life” became a common nickname for the entire system, regardless of the manufacturer.