Rolling Process Comparison

Bertsch offers a complete line of hydraulic bending rolls: four-roll double pinch, three-roll initial pinch, and the three-roll double pinch.

Easiest machine to operate since material is clamped during the squaring process and held during the entire rolling process.
Able to pre-bend, roll and post-bend the entire piece without releasing the pinch, allowing some parts to be pre-bent and the entire cylinder rolled in a single pass.
Because the plate is clamped through the entire bending cycle, a rotary encoder can be utilized to indicate how much plate has been fed through the machine, allowing it to be fitted with an optional CNC control.
Material is fed into the machine parallel to the floor, easily fitted with feed tables and side supports, or placed into a pit for ease of operation.
Less floor space is required because the part is rolled up and over right after the first pre-bend.
Machine can be fed from either direction.

Ability to pre-bend material to minimize flat.
Able to bump form easily.
Requires less floor space than three roll double pinch (both ends of the plate are preformed from the same side of the machine).
Able to square plate prior to rolling.
Machine can be easily fitted with feed tables, material supports, or set in a pit.
Material remains square throughout the entire rolling process once it is squared and pinched between the pinching rolls.
May require operator to remove plate from machine and rotate 180 degrees to pre-bend trailing edge of plate if the part requires pre-bending on both ends.

Additional open height allows you to roll smaller channel, beam or bar in the roll.
Ability to pre-bend material on both sides of machine without removing plate.
Machine requires more shop floor space when rolling larger diameter cylinders due to material hanging out both sides during the pre-bending process.
Manual plate alignment is required at both ends to square material.
Plate is fed into the machine at an angle, which can make adding side supports, feed tables or setting the machine into a pit challenging.
Requires the highest level of skill to operate, since there is no definite pinch to hold the plate from shifting during the rolling process.