9Pcs Long Hex Key Wrench

Torque is force multiplied by the length of the lever. Put the short arm into the fastener and grip the long arm, and that long arm is your lever — noticeably longer than on a medium set, so the same effort produces more turning force. On a stiff socket head cap screw, that difference is often the whole job.

But there is a limit that comes with it, and it is the key rather than the fastener that sets it. A hex key is a slender bar, and the torque you can now generate through a long lever may exceed what the key's own cross-section will carry — particularly on the small sizes, where a 2mm or 2.5mm key is very thin. Long keys snap more readily than medium ones for exactly this reason: not because they are weaker, but because they let you apply more. On small sizes, ease off.

The sizes run 1.5, 2, 2.5, 3, 4, 5, 6, 8 and 10mm.

The steel is S2, a shock-resisting tool steel. It takes a high hardness so the corners hold their shape, while retaining the toughness to twist slightly rather than shear cleanly — which is the difference between a key that deforms and warns you and one that snaps off in a recess. A snapped key inside a socket head is a serious problem, because the key is hardened and cannot simply be drilled out.

The buyers are machinery and equipment fitters, hydraulic and pneumatic technicians, motorcycle and vehicle mechanics, industrial maintenance, furniture manufacturers, and hardware dealers.

Two habits. Clean the recess and seat the key fully before turning — a hex socket is shallow, and a key bearing on the top of the flats rounds it almost at once. And use the long arm as a crank once the fastener is moving; the L-shape is two tools and switching between them is what makes these fast. Message us on WhatsApp for a price.