Long Hex Key Wrench (18x1pc)

Nobody stocks it casually. It exists for large socket head cap screws on earthmoving and construction plant, on excavator and loader attachment mountings, on crusher and screening equipment, on heavy conveyor and drive assemblies, and on the structural fixings of imported industrial machinery. It is a size that appears on a machine, is needed twice a year, and cannot be substituted when it is.

Which is the honest argument for buying it before you need it rather than on the morning you do. A machine down for want of a key is expensive in a way the key never is, and these are not sizes anyone finds in a hurry.

The technical point that belongs at this end of the range is about the fixings themselves. A cap screw of this diameter in plant that works outdoors has spent years in heat, vibration, dust and monsoon water. The threads corrode, and thread corrosion does something people underestimate: it eats the turning force. When a fastener like this is eventually reassembled and tightened, a large share of the effort goes into overcoming friction in a fouled thread and never becomes clamping load at the joint at all. The fixing reads as tight and is not, which on attachment mountings and structural plant is how components work loose in service. Clean the threads properly on the way back together. It is not housekeeping, it is the difference between a joint that holds and one that only looks like it.

On the way apart, keep the key square to the screw and fully bottomed, and accept that a key of this size is for access and for running the fastener rather than for breaking a seized one.

Forged chrome vanadium, hardened and tempered.

Buyers are earthmoving and construction plant workshops, quarry, mining and cement maintenance, agricultural machinery fitters, heavy engineering shops, and dealers supplying plant operators.

The piece count in Harden's catalogue name is their carton figure. What we sell is a single 18mm key. Tell us the machine on 94 77 111 8880 and we will confirm the size and have it on the shelf before you come. Island-wide delivery, trade quantities on request.