How to choose the power of a fiber laser cutting machine?

When your cutting line slows down or your materials come out rough and inconsistent, it’s not just a bad day—it’s a sign your laser machine isn’t strong enough.

To choose the right fiber laser power, you need to match the laser wattage with the thickness and type of metal you cut most.

Many buyers jump into fiber laser machines excited by the specs, but without understanding the practical impact of laser power. In this article, I’ll explain how to choose the right wattage for your needs, what limits a laser’s capability, and how to avoid costly mistakes. I’ll also share a real case from one of our clients at Kirin Laser who learned this lesson the hard way.

How to choose laser wattage?

You might think “more power” means “better,” but that’s not always true. Many customers end up overpaying—or undercutting their potential—by picking the wrong wattage.

The right wattage depends on your material type and thickness. Most metal fabricators need between 1kW and 6kW for daily operations.

Why laser wattage matters

Laser wattage determines how much energy the machine delivers to the material per unit time. Higher wattage machines cut faster and handle thicker materials, but also cost more, use more electricity, and need more maintenance.

At Kirin Laser, we generally recommend:

Material Type	Thickness Range	Recommended Power
Stainless Steel	0.5mm–6mm	1000W–2000W
Carbon Steel	8mm–18mm	3000W–6000W
Aluminum	Up to 10mm	3000W+
Brass/Copper	Thin sheets	2000W+
Anything above 25mm	Very thick steel or plate	10000W+

The true cost of wrong power

One of our clients—a sheet metal workshop—bought a 1.5kW fiber laser thinking it would handle most tasks. But when they started cutting 10mm mild steel, it just couldn’t keep up. The cut edges were rough, full of slag, and they had to slow down the feed rate dramatically.

We recommended upgrading to a 3kW machine. After switching, the cut quality¹ became smooth and fast. Their productivity² nearly doubled. The client later told me: “I didn’t realize I was losing money every hour with the wrong machine.”

Sometimes the price of a machine is not the issue—it’s the time you waste with the wrong one.

How thick can a 2000W fiber laser cut?

Many customers ask us this when budgeting. 2000W is a common entry-mid range power, but there are limits.

A 2000W fiber laser can cut mild steel up to 12mm, stainless steel up to 6mm, and aluminum up to 5mm with decent quality and speed.

Matching wattage to thickness

Here’s a breakdown based on our field experience at Kirin Laser:

Material	Max Thickness (Clean Cut)3	Notes
Mild Steel	12mm	Use oxygen assist
Stainless Steel	6mm	Nitrogen gas, clean edge
Aluminum	5mm	Slower speed, clean finish
Brass	2–3mm	Reflective, needs caution

When is 2000W not enough?

For businesses that need to cut 14mm+ carbon steel or any 10mm+ aluminum frequently, 2000W⁴ starts to show its limits. You'll get burn marks, need multiple passes, or risk poor kerf quality. That’s when you should look into 3kW or 6kW machines.

I always ask new customers not just what they cut now, but what they want to cut six months from now. A machine is an investment—not just for today’s jobs, but for tomorrow’s growth.

What determines the power of a laser?

Understanding what goes into “power” can help you make a smarter buying decision.

Laser power comes from its source and optics. It's determined by the laser generator’s wattage, beam quality, and how the machine delivers energy to the material.

Core components that define laser power

Let’s look under the hood:

Component	Role
Laser Source (e.g., IPG, Raycus)	Generates the beam (1000W–20000W)
Beam Delivery System	Transmits laser to cutting head5
Cutting Head	Focuses and controls the beam
Gas Nozzle and Lens	Assists material cutting
Software	Controls parameters (speed, power)

Don't ignore beam quality

Two machines can both be 3000W, but if one has better beam quality⁶ (smaller focus spot, stable output), it will cut faster and cleaner.

At Kirin Laser, we source high-end components and customize machines based on usage. For example, a client making elevator panels needs sharp corners on 0.8mm stainless steel. We used a 1.5kW IPG source with high beam stability. Their competitors with similar wattage but lower quality heads couldn't match their finish.

Laser power is not just a number—it’s how that number is used.

How to choose a fiber laser cutting machine?

This is the big question. It’s not just about power—it’s about fit.

To choose the right fiber laser cutting machine, you need to match machine power, bed size, brand support, and price to your production goals.

Five steps to choosing the right machine

1. Define your cutting needs

• What materials do you cut most?
• How thick?
• Daily cutting hours?

2. Match power accordingly

Use our earlier wattage table to narrow down your range.

3. Consider bed size

• 3015 is the most common (3m x 1.5m)
• Need to cut large plates? Go for 4020 or custom beds.

4. Evaluate support and parts

At Kirin Laser, we offer:

• OEM support⁷
• Spare parts stocked locally
• Training and video guides
• Response within 24 hours

Some lower-cost brands skip this. But when something breaks, who do you call?

5. Look beyond price

Price matters, but so does uptime. A $40K machine that works 3 shifts is better than a $30K machine that breaks every month. Also ask about:

• Cutting samples
• Warranty terms
• Delivery time

A real buyer from Texas once told me: “I bought cheap once. I paid twice.” That’s why we aim to deliver affordable, but reliable machines—not toys.

Conclusion

Choosing the right fiber laser cutting machine⁸ is about more than just wattage. It’s about knowing your needs, future-proofing your operations, and trusting a supplier that backs you. At Kirin Laser, we’ve helped hundreds of businesses scale their cutting operations with the right power, support, and machines they can rely on. Don’t just buy a machine—build a partnership that grows with you.