2.Fitting and Hand Tools

Updated on 01/04/26 by Mananjay MahatoShare on WhatsApp

1. Measuring and Marking Tools

Accuracy is the foundation of RAC fitting. Even small errors can lead to refrigerant leaks.

  • Steel Rule: Used for linear measurements; usually made of stainless steel with $0.5\text{ mm}$ accuracy.

  • Try Square: Used to check 90° angles and the flatness of a surface.

  • Scriber: A hardened steel “pencil” used to draw permanent lines on metal surfaces.

  • Center Punch: Used to create a starting indentation for drill bits. The point angle is typically 60° or 90°.

  • Vernier Caliper: Measures internal, external, and depth dimensions with high precision (least count usually 0.02 mm).

2. Holding Tools

Crucial for securing copper tubing and components without crushing them.

  • Bench Vice: Fixed to a workbench for heavy sawing or filing. Size is determined by the width of the jaws.

  • Pipe Vice: Features V-shaped jaws specifically designed to hold round pipes/tubes without distortion.

  • Hand Vice: Used for holding small screws or plates that are too small for a bench vice.

  • V-Block with Clamp: Holds round bars or tubes during marking or drilling.

3. Cutting and Finishing Tools

RAC work involves soft metals (copper, aluminum) and hard metals (steel brackets).

  • Hacksaw:

    • Frame: Adjustable or fixed.

    • Blade Pitch: Measured in teeth per inch (TPI).

      • 14–18 TPI: Soft metals.

      • 24–32 TPI: Thin tubing and hard metals.

  • Tube Cutter: Essential for copper tubing. It uses a hardened steel wheel to provide a clean, square cut without leaving metal shavings inside the line.

  • Files:

    • Flat File: General surface finishing.

    • Half-Round File: For curved surfaces and internal radii.

    • Round (Rat-tail) File: For enlarging holes or cleaning internal pipe edges.

    • Grade: Rough, Bastard, Second Cut, Smooth, and Dead Smooth.

4. Specialized RAC Hand Tools

These tools are specific to the assembly and maintenance of refrigerant circuits.

  • Flaring Tool: Used to create a 45° conical flare at the end of a copper tube to connect it to a flare fitting.

  • Swaging Tool: Used to expand the end of a tube so another tube of the same diameter can be inserted for brazing.

  • Tube Bender:

    • Spring Bender: External or internal springs to prevent kinking.

    • Lever Type Bender: Provides precise, measured angles (0° to 180°).

  • Reamer/Deburring Tool: Removes the internal burr (sharp edge) after cutting a tube to prevent turbulence and pressure drops.

  • Pinch-off Pliers: Used to permanently seal a copper charging line by crushing the tube wall before brazing.

  • Valve Core Remover: Used to replace Schreader valves without losing refrigerant.

5. Fastening Tools

  • Torque Wrench: Critical for tightening flare nuts to specific values to prevent leaks or stripped threads.

  • Ratchet Spanner (Square Drive): Specifically designed for opening/closing AC Service Valves (Stem valves).

  • Allen Keys (Hex Keys): Used for opening modern split AC service valves.

6. Key Knowledge for Exams (Quick Facts)

Tool / Concept Exam Highlight
Copper Tubing Type RAC uses “L” (thick) and “M” (thin) types.
Flaring Angle Standard RAC flares are 45°.
Files Material Usually made of High Carbon Steel.
Drill Bit Angle Standard point angle is 118°.
Brazing Heat Requires a neutral flame from an Oxy-Acetylene torch.

Safety & Maintenance

  • Mushroomed Heads: Never use punches or chisels with “mushroomed” heads; they can shatter and cause injury.

  • Pinned Files: Use a File Card (wire brush) to remove metal “pins” stuck in file teeth.

  • Oil and Oxygen: Never use oil or grease on oxygen regulators or AC gauges; it can cause an explosion.

2.Fitting and Hand Tools