G Clamp (10")

Name: G Clamp (10")
Brand: Harden
SKU: 600205

Item No. 600205

Price on request

Ten inches is the top of the G clamp range and a specific purchase rather than a general one. Nothing about it is subtle: it is a heavy casting with a long arch and a big spindle, and it is bought when the material is simply too thick for anything else — laminated beams, stacked timbers, heavy formwork, thick plate assemblies, a large workpiece with packing on both faces, or a component held to a bench or a frame with a great deal of material in between.

It is also the size where it is worth being honest about the limits of the shape. A G clamp puts all of its force through a single point on each jaw. That is exactly what you want on a small clamp — high pressure in one spot — but on a ten inch clamp holding a wide assembly, one point of pressure is not much use across a broad joint, and the temptation is to wind on more force to compensate. That does not work. The right answer is more clamps, or a caul or batten laid across the work to spread the load. Two ten inch clamps working through a stiff batten will close a joint far better than one clamp at twice the pressure, and neither the work nor the clamp gets damaged.

The frame is high grade iron casting. The arch is long here and it carries a large bending moment when the spindle is loaded, which is why the section is heavy and why the material is one that is extremely stiff in compression. The trade-off is the one cast iron always brings: it is brittle. It will not stretch, sag or creak before it goes. Hand pressure on the handle only — a bar or a pipe for extra leverage is the reliable way to break one, and a cast frame under load fails suddenly and throws pieces.

The spindle carries an acme thread, the broad trapezoidal form that carries heavy loads without deforming and keeps turning smoothly at full pressure instead of binding.

The buyers are structural steel fabricators, formwork and shuttering contractors, boatbuilders and heavy joinery shops, plant and machinery maintenance, and repair yards. Hardware dealers order this size in rather than stocking it deep.

Practical notes for the big one. Support the clamp — ten inches of cast iron hanging off a light assembly will pull it over, so let the clamp rest rather than dangle. Use cauls and packing so the pressure spreads. Watch alignment continuously as you tighten, since a clamp this powerful will move an assembly out of square before you notice. Keep the thread oiled and protected from weld spatter. And store it open, not wound down tight. Message us on WhatsApp with what you are clamping and we will tell you whether this or a deep-throat F clamp is really the tool for it.