Hand tools
Hand tools
The exam checks that you name the correct tool for a plumbing task, adjust and hold it properly, and know its limits.
Gripping and holding
- Pipe wrench (Stillson): the jaw teeth face the direction of rotation so they bite; pull the handle towards you rather than push. Used on GI and CI screwed joints.
- Chain wrench: for large-diameter or finished pipe where jaw teeth would scar the surface.
- Basin wrench: reaches tap tails behind a close-coupled basin.
- Strap wrench: chrome-plated and plastic fittings such as CPVC and chrome traps.
Cutting and shaping
Hacksaw blades: 18 TPI for thick sections and soft metal, 24 TPI for general pipe, 32 TPI for thin-wall tube and sheet. Cut on the forward stroke with long steady strokes; ease the pressure at the end so the blade does not snap. Files: flat for draw-filing, half-round for openings, round for enlarging holes.
Striking and driving
Claw hammer for nails; ball pein for riveting and centre punching; wooden or rawhide mallet for chiselling PVC and seating CI joints. A screwdriver must match the slot width - a loose fit chews the head.
Worked example
You must cut 25 mm medium GI pipe and then thread it. Reasoning: 25 mm GI is a general metal cut, so 24 TPI; clamp it in the pipe vice with the cut line about 100 mm from the jaws, start the groove with a file, and cut with light pressure. For threading, use the correct die head, cutting oil, and back off a quarter turn every one or two turns to break the chip.
Traps that cost marks
Using a pipe wrench as a hammer; an adjustable spanner on a rusted union (use the correct fixed spanner); pushing a Stillson instead of pulling; forcing a die without oil so the thread tears.