Demag Cranes FAQ: Specs, Hoists, and Emergency Parts in 2026

If you support cranes for a living, there's one thing you learn fast: emergencies rarely wait for a convenient Tuesday. In my role on a service team that supports Demag cranes and hoists, I've handled a lot of urgent calls—maybe 300 over the last decade, maybe 250; I'd have to check our CRM. The questions people ask during those calls are fairly consistent, so I put them together here as a plain-English FAQ. (Should mention: I'm writing this in April 2026, so lead times may shift after that.)

Demag is an engineering brand with a broad product range: mobile, crawler, overhead, bridge, gantry, and tower cranes. That variety is great if you need a specific machine. It also creates confusion when people search for Demag cranes and pull up the wrong document, part, or price. An informed request gets the right answer faster. That's what this page is meant to do.

Which Demag spare part do I order when our hoist is down?

Start with the nameplate, not the machine name. When someone calls and says, We need a Demag hoist limit switch, I ask the same thing every time: what does the data plate say? The type, serial number, and load capacity can change the part completely. A photo of the label usually settles it.

In March 2024, a client called at 3:15 on a Friday with an 8-tonne Demag hoist faulting on lowering. Normal part lead time was five working days; they needed it before Monday. Because we had the serial plate and a clear photo, the team identified the right brake rectifier, found it in the regional warehouse, and paid an extra $280 for Saturday courier. That sounds almost boring, but it's how most crane emergencies actually go. The delay was not the machine. The delay was a missing nameplate photo.

I do not mean to sound like a broken record, but: part number, serial number, photo. Without those, nobody can promise a correct part.

Why is the tower crane catalog hard to compare?

Because tower crane specifications are conditional. A tower crane catalog can list a maximum capacity of 14 tonnes at one radius and 3.5 tonnes at another. The jib length, counterweight, mast, and foundation installation all change the permitted load. You cannot quote a tower crane capacity as if it were a single number unless you know the configuration.

What I recommend: get the load chart for the exact model and configuration under consideration. It should show capacity at different radii, often as a curve. If someone gives you one headline number, keep asking until they show the radius. That's not a criticism; it's the physical reality of tower cranes. False assumptions are far more expensive than an awkward question.

What should an overhead crane specification guide include?

The biggest rookie mistake is treating every 10-tonne overhead crane as identical. Rated load is just one line of the spec. For a complete overhead crane system, you also need:

• Span and runway details
• Lift height and required hook approach
• Duty classification under ISO/FEM
• Crane speeds for bridge, trolley, and hoist
• Power supply, control voltage, and environment
• Options such as overload protection, VFD control, or radio remote

If you open a Demag overhead crane specification guide, you may see duty group terminology such as FEM 2m or ISO M5, not just light duty. That classification often matters more than tonnage for long-term reliability. Two cranes can both lift 10 tonnes; one may handle five lifts an hour, another forty. The second needs a heavier hoist, motor, and brake package.

Conventional wisdom says to buy extra tonnage so you have room to grow. I'd rather ask how many lifts per hour the line will run. Extra capacity gives load margin, but it does not automatically give duty-cycle margin. If you need a technical reference, ISO 4301-1 and FEM 9.511 are the classification frameworks used by crane engineers.

Demag mobile, crawler, overhead, or tower: How do I choose?

There is no universal best Demag crane. My shortcut is to match the machine to the movement pattern:

• Fixed, repeated lifting in one facility → overhead bridge or gantry crane
• Multiple locations around a site or outdoor assembly → mobile crane
• Large components and uneven ground conditions → crawler crane
• High-rise work or confined construction site → tower crane

The nuance is in duty cycle and footprint. I've seen a project almost default to a crawler crane when the actual work was repetitive indoor lifting. A bridge crane would have used less ground area, cost less to operate, and required less daily setup. On the other hand, if the job is temporary, building runway steel and electrification may not make sense.

Should I use aftermarket parts for a Demag hoist in an emergency?

I'll give you a nuanced answer because I support genuine Demag parts, and I've also seen good aftermarket components work when selected carefully.

For safety-critical components—brakes, limit switches, overload devices, wire rope, load-bearing fixtures—I stay with genuine parts that have clear documentation. In an emergency, the part that matters is the one that matches the design intent and can be verified. A lower-priced part is not a bargain if it fails under load; it's a hazard. That is not a sales slogan. It's a risk-control rule.

For non-critical consumables or structural items that do not affect lifting safety, a carefully selected generic may be acceptable. But I would not start that experiment at 4 pm on a Friday. The surprise in my experience is not that OEM parts cost more. The surprise is how often the wrong aftermarket part gets returned and replaced—by which time the rush freight costs outweigh the original savings.

Why do people search for Demag excavator when they need cranes?

That is a common mix-up. The Demag name has a long history in heavy machinery, including very large mining excavators as well as cranes. When you search Demag excavator, you might see hydraulic mining shovels or bucket-wheel excavators that share German engineering heritage but are not the same product line as the Demag cranes and hoists discussed here.

This matters for parts and technical support. A Demag excavator needs its own model number, serial number, manuals, and support channel. Do not assume that hoist components, overhead crane parts, or tower crane documentation will transfer to an excavator. The inverse is also true: an excavator user should not call a crane service center expecting hydraulic shovel parts. Checking the equipment type in the first minute saves hours of missent parts.

What is realistic when a Demag crane must be back up in 36 hours?

This is my favorite kind of question because it means the customer is thinking about outcomes, not just price. Let's separate two situations.

A stocked spare part for a common Demag hoist can often ship the same business day and arrive next day by air freight, depending on warehouse location and customs. If a local service technician is available, replacement may only take a few hours. In that case, 36 hours is realistic.

A non-stocked custom hoist, special drum, or obsolete component is different. It may require manufacturing or international sourcing, and nobody can outrun physical logistics. That is when early communication matters most. If I know by Tuesday that a part will take eight working days, the customer can plan. If I find out Thursday, everyone loses time.

The value of guaranteed turnaround is not just speed; it's certainty. There's something satisfying about taking a crane that seemed down for a week and getting it back before the client's deadline. After the stress and courier charges, seeing the hook move again is the payoff. The best result happens when we ask the ugly questions up front: Is the part available? Do we have enough time? And what's the backup plan if the answer is no?