Chicago Dreis & Krump Hydraulic Press Brake machines and Edwards Shop Press with Brake Tooling

To bend metal, Press Brake machines normally use a wedge shaped upper die that force the metal down into the V shaped lower die to bend metal to conform with the tooling.

Click for 4 pages of standard Press Brake Dies. A Back Gauge can position the metal exactly where you want it, and the Ram Depth Control is used to stop the upper die at the correct depth down into the lower die to form the angle desired. Sophisticated tooling can be used to form several bends simultaneously. The size of machine required is normally determined by the thickness of the metal and width of the bottom V-die used.

Air Bending is when the upper die (punch) pushes the metal down into the bottom die without bottoming the metal into the bottom die. When the punch is raised, the metal retracts a little from the air bend position. The amount of the retraction is the spring-back. The amount of spring back depends on the type of metal, the thickness, grain direction and hardness. You should expect less than 5 degrees of spring back unless you are bending a hard metal like stainless steel. Expect the inner bend radius to be slightly greater than the radius of the punch. Air bending is the method normally when calculating the tonnage required. Click for our Press Brake Tonnage Chart Chart to estimate the size machine you need.

Bottoming (or Coining) is when the upper die (punch) pushes the metal all the way down into and against the bottom die. This causes the metal to take the shape of the die set and results in very little spring back. Coining happens if you push the metal down hard into the bottom die. The minimum inner radius of the metal should be equal to at least one metal thickness. Warning: Coining can easily crack brittle metals such as aircraft aluminum. Coining requires more tonnage from your brake press machine than does bottoming which requires more tonnage than does air bending.

Chicago Dries & Krump brake presses use American style tooling and come with a simple 2-Axis CNC controlled back gage and ram die depth control with a 16 bend memory to easily form your simple or complex parts jobs again and again. 99 jobs can be saved in memory. To program the memory you simply make your first part manually and save the ram depth and back gauge positions in the CNC memory. Whenever you make the same part again the machine knows what to do. You just have to position the metal against the back gauge. Metal forming can also be done in a manual mode for single parts.

Click if you are looking for an electric-hydraulic power leaf brake machine to fold your metal.

NOTE: Safety devices such as Light Curtains are strongly recommended to prevent fingers and hands from getting crushed especially for predictable repeat uses. Safety compliance is the users responsibility. Please take it seriously.

**Click for our Machinery Safety webpage**

Click for chart of tensile strengths for aluminum and stainless steel to compare with mild steel Click for a Bend Radius Chart for aluminum and stainless steel