This is Pressing!

While puns aren’t important, some basic knowledge on a press brake can be!

What is a press brake?

Well, it’s basically a big machine that presses sheet metal (usually) using a set of what is called “tooling dies” to form a bent work piece. With that use, they’re loosely referred to as a “benders”.

There are several different models of press brake, but they all share the same job to produce a similar result.

If you want a very detailed write up on these brilliant machines, you can follow this link: (https://www.thefabricator.com/article/bending/understanding-modern-press-brakes)

Depending on your needs, you could get a few different types…

Type 1 Hydraulic

Most common press brake with the longest history. These machines can handle heavier workloads, averaging 100-300 tons of pressure, but machines can be over 50ft long and weigh over 2500 tons themselves. [That’s a big machine].

Type 2 Electric

These brakes require less maintenance and do not ever leak oil (since there is no hydraulic oil in them). They’re smaller, faster, lighter and more efficient because the motors are not continuously running to keep hydraulic pressure built up.

Finger Brake/ Box & Pan Brake

• Named for it’s use to form box and pan shapes.
• Contains several removable blocks on it’s “clamping bar” which can be arranged to bend only the intended areas.

A clamping bar comes down to hold the material firmly during a bend. This action may be manual or automatic depending on the brake.

• The bends can be made to any reasonable angle up to 120 degrees.
• If the bend needs to be sharper, it can be made into a “hem bend“.

A hem bend is achieved by making an initial bend (very sharp angle), then re-inserting the work piece under the clamping bar and lowering it to “fold it over on itself”.

Tooling

Several different types of dies exist to be used on these machines, but the ones I am familiar with are “Gooseneck Dies” which are extra deep to give the work piece clearance so it does not bang against the tooling (this is used for parts with a protruding flange typically).

The other type of tooling familiar in my line of work are “V-Dies“. These simply are used to create v-shaped bends. While these make bends, the tooling does not touch each other, leaving no bend perfectly “V” shaped, there is actually a radius on the outside corner of the bend making it more of a lazy “V” or a sharp “U” shape, depending on the dies used.

While dies are used to bend the material, press brakes can utilize punch tooling to separate/cut material. Punch tooling contacts the upper and lower tooling together.

Safety Tips

Some of these machines can be in excess of 10ft long, so the work piece can be quite wide. In this case, it’s wise to ask for assistance from a helper to allow for maximum control while making the bend.

Without help, there is a chance the material will compress and spring up, possibly striking the operator if they’re not paying attention.

Also, keeping hands and limbs out of the “curtain” of the machine will allow the operator to keep their fingers in operation for much longer. New machines may have safety features to disable and further pressing of the machine if something foreign passes in front of the laser safety area.

Maintenance

Any hydraulic machine should be regularly checked for oil level and normal operation.

Referring to the operators manual is always recommended to ensure proper maintenance is being followed through on. The last thing anybody wants is the machine that cost hundreds of thousands of dollars to break due to neglect.

Knowing what to do

Knowledge of these machines can be gained through research, reading manuals, and by hands on experience.

What not to do should be common sense, and if it’s not, perhaps the prospective operator should pursue other opportunities within the company, or they’ll have to get very good training to compensate for any missing mechanical ability.