Definition
A large machine tool used in sheet metal work to bend flat metal stock into precise angles. The workpiece is placed over a die, and a long upper ram presses down to form the bend along a straight line.
Plain English
A machine that bends flat sheet metal into a sharp, straight angle by pressing it down into a shaped slot.
Context Anchor
Seen in aircraft maintenance and sheet-metal repair when a part, bracket, rib, or panel edge must be bent to a specified angle.
Derivation
‘Press’ comes from the Latin pressare, meaning to push hard against. ‘Brake’ here is unrelated to stopping a vehicle — it comes from an old English word for a tool that crushes or works material. Together: a machine that presses metal into shape.
Why Pilots Care
A part bent on a press brake can fit properly and keep its intended strength. A poor bend can make a repair part weak, misaligned, or unsuitable for installation.
Intuition Check
Do not read “brake” here as a stopping device. A press brake does not slow the aircraft; it bends sheet metal in a shop.
Example Sentence 1
The mechanic used the press brake to form a 90-degree flange along the edge of the aluminum repair patch.
Example Sentence 2
After cutting the aluminum, the technician ran the sheet through the press brake to create the required 90-degree bend.