Hand Tools and Equipment: Selection, Use and Care
This domain examines whether you can choose the right hand tool for a job, use it correctly, and recognise the common abuses that damage tools or injure the user.
Spanners and sockets
Open-end spanners have two jaws offset about 15 degrees and are used where a ring spanner will not fit; they grip on two flats only. Ring (box) spanners grip all six corners and suit tight or partly rounded nuts. A combination spanner gives one of each. Adjustable spanners are for odd sizes and light duty only - they slip and round off hexagons under load. Socket sets with a ratchet handle are used with extensions for recessed bolts. A torque wrench is used only for tightening to a specified figure, never as a breaker bar and never to loosen.
Cutting and striking tools
Hacksaw blades: 18 teeth per inch for thick solid bar and hard metal, 24 TPI for thin tube and sheet. Teeth point forward, the cut is made on the forward stroke, and the full blade length is used with light pressure. Files are single cut for sharpening and double cut for fast metal removal; grades run from rough through bastard and second cut to smooth. Clean a file with a file card, never hammer it, and always fit a handle. A chisel whose head has mushroomed must be ground back before use. Hold a hammer near the end of the handle and strike with the face square to the work.
Gripping, holding and measuring
Screwdriver tip width and thickness must match the slot. Pliers are for gripping and cutting, not for high torque. Use a bearing puller for bearings - never hammer a bearing race. Feeler gauges set tappet clearances and spark plug gaps.
Worked example
A cylinder head bolt must reach 60 N·m. Fit the correct socket, set the wrench to half the figure (30 N·m) and tighten all bolts in a spiral from the centre outwards, then repeat at 60 N·m. Do not use the wrench to slacken the bolt afterwards; the ratchet and spring are calibrated for tightening only, and loosening shocks will destroy that calibration.
Traps that cost marks
Open-end spanner on a very tight nut; adjustable spanner used for high torque; hacksaw blade fitted with teeth pointing backwards; chisel with a mushroomed head; file used without a handle.