BTEB Welding Exam cheat sheet

SMAW (arc welding) uses a consumable coated electrode; the coating shields the arc, stabilises it, and forms slag to protect the cooling weld.

The electrode classification E6013 means: minimum tensile strength 60,000 psi (≈ 420 MPa), usable in all positions (1), and a rutile-type coating with AC or DC capability (3).

Arc voltage is a function of arc length; typical SMAW arc voltage is 20–35 V, while current (amperage) controls penetration and deposition rate.

For GMAW, the transfer mode depends on current density and shielding gas: short-circuiting (low current), globular (medium), and spray (high current with ≥ 80% argon).

Oxy-acetylene neutral flame temperature is approximately 3,200 °C; a carburising (excess acetylene) flame has three zones and is used for hardfacing and aluminium.

Weld joint types are butt, lap, T-joint, corner, and edge; weld types are groove, fillet, plug, spot, and seam.

Distortion control methods include back-step welding, balanced (alternating) welding, pre-setting, and using the fewest passes consistent with the joint design.

Common weld defects: porosity (gas entrapment), slag inclusion, lack of fusion, undercut, and cracking; each maps to a specific cause such as damp electrodes, low current, or high travel speed.

BTEB practical assessments typically require a butt joint in the flat position using SMAW with visual inspection against acceptance criteria for bead uniformity, spatter, and undercut.

PPE for arc welding: welding helmet with correct shade lens (shade 10–13 for SMAW), leather gloves, flame-retardant apron, safety boots, and ear protection when chipping slag.

Eye protection must be worn at all times in the workshop; chipping slag requires clear safety glasses under the helmet to prevent eye injury.

Before arc welding, check electrode holder insulation, earth clamp connection, cable condition, and that the work return cable is attached to the workpiece, not to the bench frame.

Fire prevention: remove flammable materials within 10 m of the arc, use fire blankets, and keep a suitable extinguisher (dry powder or CO₂) within reach.

Cylinder safety: store oxygen and acetylene upright and separately, secure with chains, keep caps on when not in use, and never use oil or grease on oxygen fittings.

Acetylene cylinder pressure must never exceed 1.5 bar (≈ 15 psi) in use; use a flashback arrestor on both hoses and a pressure regulator on each cylinder.

Electrical safety: welding machines must be earthed; do not change electrodes with wet hands; isolate the machine before changing cables or performing maintenance.

Ventilation: welding fumes must be extracted at source; in confined spaces use forced ventilation and a trained standby person outside the space.

Housekeeping: keep walkways clear, coil cables off the floor, store hot work pieces in a marked area, and allow weldments to cool before handling.