What does 100 tonne × 3 metre mean on a press brake?

The machine can press with up to 100 tonnes of force and bend sheet up to 3 metres long.

How do I know what tonnage my bend needs?

It depends on thickness, length, material strength and V-die opening. Workshops use bending charts or the CNC's calculator; giving them the drawing with material and thickness is enough.

After bending, the metal springs back slightly towards flat. Operators over-bend a little to allow for it; it is larger in stainless and high-strength steel.

← Back

Press brake

Also called: CNC press brake, bending machine, sheet metal bending machine, hydraulic press brake

A press brake bends sheet metal and plate by pressing it with a punch into a V-shaped die. A CNC back gauge positions the sheet for each bend, so boxes, brackets, channels and panels come out at the right angles and sizes.

Quick facts

Size: Given as tonnage × bending length, e.g. 100 t × 3 m
Drive: Hydraulic (most common), electric (servo) or mechanical
CNC axes: Ram (Y1, Y2) and back gauge (X, R, and more on larger machines)
Typical angle accuracy: About ±0.5° with a good setup
Tools: Punches and V-dies; the V opening depends on sheet thickness
Works with: Mild steel, stainless steel, aluminium and other sheet metals

How it works

The sheet rests on the die and against the back gauge. The ram brings the punch down and presses the sheet into the V; how deep it goes sets the bend angle. The CNC moves the back gauge for each bend in turn, so a part with many bends is made in one sequence.

Tonnage and tooling

Bending force rises with thickness, length and strength of the material; stainless needs more force than mild steel
A common rule of thumb is a V opening of about 6–8 times the sheet thickness for mild steel
Smaller V gives a tighter inside radius but needs much more force
Special punches (gooseneck, acute angle) and hemming tools make more complex shapes

Design tips for bent parts

Keep flanges long enough to rest on the die: very short flanges cannot be bent
Keep holes away from bend lines, or they will stretch out of shape
Use one inside radius for all bends where possible
Allow for springback, especially in stainless steel and high-strength steel
Put bend reliefs at corners where two bends meet

Need work done on a Press brake?

Post your requirement free. Workshops that take your kind of work see it and get in touch. You only talk to the ones that fit.

Get started

Related job work

Machines

Materials

Questions

What does 100 tonne × 3 metre mean on a press brake?: The machine can press with up to 100 tonnes of force and bend sheet up to 3 metres long.
How do I know what tonnage my bend needs?: It depends on thickness, length, material strength and V-die opening. Workshops use bending charts or the CNC's calculator; giving them the drawing with material and thickness is enough.
What is springback?: After bending, the metal springs back slightly towards flat. Operators over-bend a little to allow for it; it is larger in stainless and high-strength steel.

The figures on this page are typical values for guidance, written by Diemeco from standard engineering practice. They are not a specification: confirm grades and properties with the relevant standard or the supplier's mill test certificate, and tolerances with your workshop. Last checked 8 October 2026.