Used Back Geared OBI Presses for Sale • Geared C-Frame Presses

Used and new back geared OBI presses (geared C-frame presses) from 39 to 275 tons, mostly Komatsu, Aida and Stamtec, in stock in Michigan and Tennessee. Filter by tonnage, stroke, shut height, speed and features below.

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Used Back Geared OBI Presses in Stock

A back geared OBI press is a C-frame (gap frame) mechanical stamping press with a gear reduction between the flywheel and the crankshaft. The flywheel spins fast and the gears slow the crank down, multiplying torque, so the press delivers more energy on each stroke at lower speeds than a direct-drive flywheel OBI press. That makes it the choice for forming, drawing, coining and thicker material. Every press on this page is owned and warehoused by us in Jackson, Michigan or Columbia, Tennessee, so you can ask for a video or schedule an in-person inspection with your salesperson before you buy.

We keep more than 100 back geared OBI presses in stock, from about 39 to 275 tons. Komatsu is the builder we carry most, including new Komatsu OBS presses and H1F servo presses, along with used Aida, Stamtec, Minster, Niagara, Seyi and South Bend Johnson presses.

Back Geared vs. Flywheel OBI Presses

 Back gearedFlywheel (direct drive)
DriveFlywheel turns the crank through a gear reductionFlywheel mounted right on the crankshaft
SpeedSlower, mostly 100 SPM and underFaster, often 100 SPM and up
Energy per strokeHigh: more work available deeper in the strokeLower at slow speeds; relies on flywheel speed
Best forForming, drawing, coining, thick material, longer strokesBlanking, piercing and fast progressive work in thinner stock

What Does OBI Mean?

OBI stands for open back inclinable. The frame is open at the back so parts and scrap can drop out, and the original design could tilt back so parts slid out by gravity. Most modern C-frame presses are built rigid instead, sometimes called OBS (open back stationary). In practice, "OBI press," "gap frame press" and "C-frame press" are all used for the same family of single crank presses. See all OBI presses, or gap frame double crank presses for wider dies.

Features to Look For

  • Clutch and brake. Most have air friction clutches; wet clutch presses run cooler and quieter with less maintenance.
  • Hydraulic overload. Protects the press and die on a double hit or misfeed. Most presses here have it.
  • Air counterbalance. Carries the slide and upper die weight, for smoother running and easier slide adjustment.
  • Variable speed drive. Lets you slow down for deep forming and speed up for lighter work.
  • Servo drive. Komatsu H1F servo presses let you program the slide motion, slowing at the bottom for forming and coining.
  • Cushion and slide adjust. A die cushion for draw work, and motorized slide adjustment for faster die setting.

How to Choose a Back Geared OBI Press

  • Tonnage and rating point. Mechanical presses reach full tonnage only near the bottom of the stroke. Geared presses carry their rated tonnage higher in the stroke, which matters for forming.
  • Stroke and shut height. Long enough to form the part and clear it; the shut height and slide adjustment must fit the die.
  • Bed size. Check right-to-left and front-to-back for your die and feed.
  • Speed. Match the SPM range to the operation: forming and drawing usually run slower than blanking.

Back Geared OBI Press FAQ

What is a back geared press?

A mechanical press with a gear reduction between the flywheel and the crankshaft. The gears multiply torque, so the press has more energy per stroke at slower speeds, which suits forming and heavier material.

Back geared or flywheel press: which do I need?

Choose back geared for forming, drawing, coining or thick material at moderate speeds. Choose flywheel for fast blanking and piercing in thinner material.

What does OBI stand for?

Open back inclinable: a C-frame press with an open back for part removal, originally able to tilt back. Today the term covers most single crank C-frame presses.

Do you sell new back geared presses?

Yes. We sell new Komatsu OBS gap frame presses and H1F servo presses alongside our used inventory.

Can I see a press run before I buy?

Ask for a video, or schedule an in-person inspection with your salesperson at our Jackson, Michigan or Columbia, Tennessee warehouse.

Do you buy used OBI presses?

Yes. We buy single presses, complete press lines and full plants. See sell your machinery or send us photos and the nameplate.

Inventory changes every week, and some presses arrive before they are listed. If you don't see the press you need, contact us with your tonnage, stroke, bed size and die details.