Heavy Duty F Clamp (80x300)

Name: Heavy Duty F Clamp (80x300)
Brand: Harden
SKU: 600303

Item No. 600303

Price on request

The number to look at on this clamp is the 80, not the 300. Eighty millimetres is the throat depth — how far in from the edge of the work the jaws will reach before the bar gets in the way — and it is the specification most people ignore when buying clamps and then curse afterwards. Capacity is easy to judge by eye. Throat is not, and no amount of opening helps when the pressure needs to be 70mm in from an edge and the clamp will only reach 50.

Eighty millimetres of throat opens up a whole class of work: gluing a panel where the joint runs down the middle rather than at the edge, clamping a batten across a board, holding a repair patch in the field of a sheet, fixing a fitting some way in from the rim, and any assembly where the edge of the material is not where the pressure needs to be. Paired with a 300mm opening, it handles most cabinet and joinery components as well as reasonably thick built-up work.

The clamp works the way all F clamps do, and the reason they have largely replaced G clamps on site is speed. The lower jaw slides down the bar by hand until it meets the work, then locks by friction as soon as load comes onto it, so the screw only has to close the last few millimetres. Setting one takes moments. All of that depends on the bar staying smooth, which is why it is nickel plated — a rusted or gummed-up bar is a sliding jaw that either will not move or will not hold.

The threaded spindle has a black finish, and the handle is a two-component moulding: a hard internal structure for strength with a softer outer layer where your palm goes.

The buyers are cabinet makers and furniture workshops, joiners and shopfitters, sign and display makers, boat and vehicle body repairers, and general fabrication and maintenance. Hardware dealers supplying woodworking trades stock the deeper-throat clamps for exactly this reason.

Two practical points that follow from the deep throat. Deeper reach means a longer lever arm between the jaw and the bar, so the clamp is working its frame harder at full pressure than a shallow one — tighten firmly by hand and leave it there rather than reaching for something to lever with. And a deep-throat clamp on thin sheet will bow the sheet if all the pressure lands on one small pad, so put a batten or caul across to spread it. Keep glue off the bar, use packing on finished faces, and store the clamps hanging rather than in a heap where the bars get scratched. Ask us on WhatsApp and we will quote a mixed set matched to your work.