What are the three basic types of metal cutting saws?

Metal cutting saws are essential tools used extensively in metalworking applications such as welding, fabricating, and construction. They utilize abrasive blades to cut through various types of metals quickly and efficiently. There are three main types of metal cutting saws: hand saws, power saws, and cold saws. Each has distinct characteristics and is suited for different uses.

Hand Saws

Hand saws, also known as hacksaws, are a basic type of metal cutting saw operated completely through manual labor. They consist of a C-shaped metal frame that holds a removable blade tightly in place. Users grasp the handle on the frame and push and pull the blade back and forth to cut through metal.

Hacksaws utilize disposable high carbon steel blades approximately 10-12 inches long. The blades feature tiny cutting teeth running along their length spaced approximately 32-40 teeth per inch. As the teeth cut, small metal chips break off the workpiece with each stroke. The small teeth enable hacksaws to make detailed curved or straight cuts.

While hacksaws are slow and labor-intensive compared to power saws, they have distinct advantages. They are highly inexpensive and portable. Their simplicity also makes hacksaws very user-friendly for DIY work. Common types of hand hacksaws include:

  • All-purpose hacksaws – The most common type with a frame adjustable to fit 10-12 inch blades for cutting various metal thicknesses.
  • Junior hacksaws – Feature smaller 8 inch blades for cutting thin material in tight areas.
  • Close quarter hacksaws – Have an extended narrow frame allowing blade access in confined spaces.

Hacksaws are ideal for short, small-scale, low volume cutting jobs. Their key benefits include:

  • Inexpensive compared to power saws
  • Highly portable
  • Can make curved cuts
  • Easily replaceable blades
  • Does not require electricity

However, hacksaws do have some downsides:

  • Slow cutting speeds
  • Labor-intensive operation
  • Not suitable for high volume cutting
  • Difficult to cut thick material
  • Blades may break under pressure

Power Saws

Power saws utilize electric motors or alternative power sources to mechanically drive the saw blade. This allows them to cut much quicker through thick, rigid metals with less operator effort. They are available in several types optimized for different functions.

Circular Saws

Circular saws employ a rotating circular saw blade to make cuts. Popular types include miter saws, chop saws, and portable cut-off saws. The main circular saw benefits are:

  • Fast cutting speeds – increased productivity
  • Powerful motors – can cut thick material
  • Makes straight or angled cuts
  • Available in portable sizes

Drawbacks of circular saws include:

  • Typically only make straight cuts
  • Generate high noise/dust
  • Increased hazards from exposed blade

Band Saws

Band saws consist of a continuous metal band or ribbon with cutting teeth running around two large pulley wheels. Benefits include:

  • Can make straight or curved cuts
  • Cooler operation than friction blades
  • Blade fully enclosed for safety

Limitations include:

  • Large equipment can be expensive
  • Not very portable
  • Prone to blade breakage

Reciprocating Saws

Reciprocating saws, also called sabre saws, feature a metal cutting blade moving in a rapid back and forth motion. Advantages:

  • Compact and portable
  • Can make plunge cuts
  • Good for demolition work

Disadvantages:

  • Rougher cut quality
  • Limited thickness cutting ability
  • Produce high vibrations

Abrasive Cutoff Saws

Abrasive cutoff saws utilize abrasive discs similar to grinding wheels to cut through metal. Benefits include:

  • Portability
  • Low dust generation
  • No coolant required
  • Cuts cleanly with no burrs

Downsides include:

  • Slower than friction blade saws
  • Disks wear down over time
  • Limited thickness cutting ability

Cold Saws

Cold saws utilize chilled coolant to keep the metal and saw blade cold while cutting. This prevents damaging metal alloys or producing heat affected edges. Types of cold saws include:

Chop Saws

Cold chop saws function similarly to miter saws but with coolant spray. Benefits are:

  • Fast cuts with no damage to metal
  • Mitigates sparks, burns, or discoloration
  • Prevents metal hardening during cutting

Limitations include:

  • More expensive than friction saws
  • Requires handling coolant

Band Saw Cold Saws

Cold band saws are continuous band saws with coolant nozzles. Advantages:

  • Fast, clean cuts on thick materials
  • Minimal post-cutting cleaning needed
  • Curved cutting ability

Disadvantages:

  • Higher equipment cost
  • Not very portable

Abrasive Wheel Cold Saws

Abrasive wheel saws with coolant produce clean burr-free cuts. Benefits:

  • Cut soft or hard metals without damage
  • Low maintenance equipment
  • Simple operation

Limitations:

  • Slower feed rates than band saws
  • Possible wheel clogging over time

Conclusion

The three main types of metal cutting saws each have unique strengths ideal for different applications:

  • Hand saws – Portable, inexpensive, can make curved cuts
  • Power saws – Faster cutting, thicker capacities, good for high production
  • Cold saws – Damage-free cuts, ideal for delicate alloys

When selecting a metal cutting saw, key factors to consider are cut quality, portability needs, metal thickness, production volume, cut types required, equipment costs, and operator skill level. Utilizing the correct saw type for the intended purpose will optimize cutting performance and efficiency.