Tools for Sheetmetal Construction and Repair

Why is cold forming preferred over hot forming in aircraft sheet metal repairs?

It eliminates heat-induced warping and extra processing

Which tool allows shaping of a sheet metal edge into a bead or flange?

Rotary machine

Which tool is best suited for replicating hole placement in a patch from existing aircraft structure?

Hole duplicator

What function does the backstop on a squaring shear serve?

Ensures multiple cuts are identical in size

Why is a 135° split-point drill bit recommended for aluminum?

It reduces walk-off and improves penetration

What advantage does a combination square provide during layout operations?

It allows for measurement of 90°, 45°, and adjustable angles

Why should you avoid reversing a reamer out of a hole?

It can force chips into the metal surface and scar the hole

Which forming tool allows fabrication of complex box shapes not possible on a cornice brake?

Box & pan brake

Why is cetyl alcohol preferred as a lubricant when drilling aluminum?

It liquefies under heat and helps chip removal

What is the purpose of using a chip chaser during sheet metal work?

To clean between metal layers after drilling

What makes the Kett saw preferable for cutting damaged stringers compared to other cutting tools?

It allows angular cuts and doesn't need a starting hole

Why are disc and belt sanders preferred over files in some trimming operations?

They are faster and more precise for dimension adjustments

Why is a fiber-tipped pen preferred over a No. 2 pencil when marking aluminum?

Graphite from pencils can cause corrosion

What is the most effective way to avoid cracking during stretching operations?

Deburr or polish the edges of flanges before stretching

What is a critical technique for drilling large holes with precision?

Pilot drilling followed by step reaming to size

Which safety precaution should always be followed when using a grinder?

Wear goggles even if shields are attached

What makes the automatic center punch preferable in certain applications?

It requires no hammer, increasing precision and safety

What is the main risk of using excessive downward pressure when operating a reciprocating saw?

It may break the blade and distort the cut

What characteristic makes the English wheel a valuable tool for double curvature panels?

It stretches and smooths the metal with controlled shaping

What makes a slip roll former ideal for producing cylindrical shapes?

It allows progressive bending with adjustable rolls

How should drill bits be tested for usability before beginning work?

By running the motor freely to observe wobble or vibration

Which marking tool should only be used when the mark will be removed later in the process?

Scribe

When is a pin punch typically used during disassembly?

To finish driving out a pin after starting with a drive punch

What critical error might occur if a center punch is struck too hard?

It causes distortion or protrusion through the sheet