1/2" Hexagon Socket (18mm)

Name: 1/2" Hexagon Socket (18mm)
Brand: Harden
SKU: 535518

Item No. 535518

Price on request

Eighteen millimetres is the alternative head size for M12, used by a number of Japanese manufacturers where others use 17mm, and it appears widely on light commercial vehicles, trucks and machinery imported from Japan — which in Sri Lanka means it comes up a great deal more often than in markets where European vehicles dominate.

That is a useful thing to know when buying, because socket sets sold on price often include 17 and skip 18, on the assumption that the two are interchangeable. They are not. A 17mm will not fit an 18mm nut, and a 19mm on an 18mm nut engages only at the corners, which is precisely how fasteners get rounded. Anybody working on Japanese light commercials, buses or agricultural machinery should make sure 18mm is in the tray.

The size is doing structural work: suspension and steering fixings, engine and gearbox mountings, propshaft and driveline bolts, chassis and body mounting bolts, and heavy bracketry. Fasteners at this size are usually tight, frequently corroded from living underneath a vehicle, and need to be reassembled to a specified torque, because a mounting bolt that is loose works itself looser and one that has been over-tightened has been stretched.

The socket is drop forged from fine chrome vanadium with a matt chrome finish. Forging heats the steel and hammers it into a die so its internal grain flows around the hexagonal form rather than being cut through it, which matters at the six corners of the hex where all the stress concentrates. Chrome vanadium gives hardness and wear resistance from the chromium and toughness and grain refinement from the vanadium, and the chrome plating resists the oil, water and salt the tool lives in.

The buyers are commercial vehicle, bus and truck mechanics, light commercial and van workshops, agricultural and plant fitters, general engineering and maintenance, and hardware dealers supplying the motor trade.

Three habits. Seat the socket fully on the fastener before applying force, because one engaged only at the tips of the hex rounds nuts. On a seized bolt, use penetrating oil and patience rather than a longer bar — shearing a suspension bolt inside its bush costs far more time than waiting does. And never use a chrome hand socket on an impact wrench: plated hardened chrome vanadium is brittle under hammering and can crack and throw pieces. Impact guns need black chrome molybdenum impact sockets. Ask us on WhatsApp for a price.