Weight Comparison of U Type vs Z Type Sheet Piles

You are reviewing a project specification, and the engineer has given you a choice between U type and Z type piles. The budget is tight, and you need to make the right call.

U type and Z type sheet piles¹ have different weight distributions for the same structural performance. Z piles typically offer a higher section modulus per kilogram of steel, meaning they can be lighter than U piles while achieving the same bending resistance.

I learned this lesson early in my career when a client in Saudi Arabia asked me to quote both options for a deep excavation project. The U piles were heavier but seemed simpler. The Z piles were lighter but looked more complex. The weight difference surprised me. Let me share what I have discovered about these two profiles over years of supplying them to projects around the world.

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What is the difference between U type and Z type sheet piles?

When you stand two piles side by side, the shape difference is obvious. But the weight difference is what matters for your shipping budget and your crane requirements.

The main difference is the position of the interlocks and the resulting structural efficiency. U piles have interlocks at the neutral axis¹, which makes them symmetric and easier to handle. Z piles have interlocks at the outer flanges, which pushes more steel away from the center and gives higher strength for the same weight .

How Shape Affects Weight and Strength

Let me walk you through the engineering behind these shapes.

U Type Characteristics²
U piles are symmetric profiles that look like a shallow trough. The interlocks sit right in the middle of the section, near what engineers call the neutral axis. This design makes the pile very stable during driving. You can rotate it, interlock it from either side, and it is forgiving on site . For the riverbank project in Southeast Asia, we used U piles because the installation crew needed that simplicity.

But there is a trade-off. Because the interlocks are near the center, the steel is concentrated close to the bending axis. This means you need more steel weight to achieve a given section modulus. The U shape is less efficient structurally, but it is more practical for many jobs.

Z Type Characteristics³
Z piles look like a zigzag. The interlocks are at the outer corners, far from the neutral axis. This design puts the steel where it works hardest to resist bending . For the same weight, a Z pile can resist much more soil pressure than a U pile.

The Z shape also allows for wider sections. Some Z piles are over 675 mm wide, which means fewer pieces to handle and drive for the same wall length . This saves installation time and labor costs.

Real Weight Comparisons
Here is a direct comparison from real products:

Profile Type	Width (mm)	Height (mm)	Thickness (mm)	Weight per Meter (kg/m)
U Type (400×125)	400	125	13.0	60.0
Z Type (WRZ16-635)	635	379	7	61.5
U Type (600×210)	600	210	18.0	106.2
Z Type (WRZ34-675)	675	490	12	118.9

Notice how the Z piles achieve similar or better strength with different thicknesses. The 675 mm Z pile is 12 mm thick but weighs 118.9 kg/m, while the 600 mm U pile is 18 mm thick and weighs 106.2 kg/m. The Z pile is actually heavier here because it is much taller and wider, giving it far greater strength.

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How much does sheet piling weigh?

This is the question I answer almost every day. The short answer is that sheet piling weights¹ vary widely based on profile, thickness, and length.

Sheet piling typically weighs between 40 kg/m and 150 kg per meter for common profiles. For a standard 12-meter length, a single pile can weigh anywhere from 480 kg to 1,800 kg. The weight depends on the specific section and its dimensions .

Weight Ranges by Profile Type

Let me give you a practical reference based on real products I have supplied.

U Type Weight Ranges
U piles come in many sizes. Here are common examples:

Profile	Width x Height (mm)	Thickness (mm)	Weight per Meter (kg/m)
Light U	400 x 100	10.5	48.0
Medium U	400 x 125	13.0	60.0
Heavy U	400 x 170	15.5	76.1
Extra Heavy U	600 x 210	18.0	106.2

Z Type Weight Ranges
Z piles often achieve higher strength with different weight distributions:

Profile	Width x Height (mm)	Thickness (mm)	Weight per Meter (kg/m)
WRZ12-650	650 x 319	7	57.8
WRZ16-635	635 x 379	7	61.5
WRZ18-635	635 x 380	8	70.1
WRZ30-635	635 x 420	12	113.3
WRZ34-675	675 x 490	12	118.9

What These Numbers Mean for Your Project
A 12-meter pile weighing 60 kg/m gives you 720 kg per piece. A 15-meter pile weighing 106 kg/m gives you 1,590 kg per piece. Your crane and transport need to handle these weights.

I had a client in Pakistan who ordered 400×170 U piles at 76.1 kg/m . Each 12-meter pile weighed 913 kg. He had to upgrade his site crane because his original equipment could only handle 800 kg. That was an unexpected cost. Always check the weight before you commit to handling equipment.

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How much does a PZC 13¹ sheet pile weight per foot²?

This is a specific question that comes up often for projects using American standard piles. PZC 13¹ is a common Z profile in the US market.

A PZC 13¹ sheet pile weighs 50.4 pounds per foot. This comes from the manufacturer’s data sheet, which lists the weight per linear foot for this specific section .

Understanding PZC Series Weights

Let me break down the PZC series so you have a complete reference.

PZC Series Specifications
The PZC series is manufactured by Gerdau Ameristeel and features a ball-and-socket interlock design. These sections are wider, lighter, and stronger than traditional Z profiles .

Here are the weights for the full PZC range:

Section	Nominal Width (in)	Height (in)	Weight Per Foot (lbs/ft)
PZC 12	27.88	12.52	46.4
PZC 131	27.88	12.56	50.4
PZC 14	27.88	12.60	55.0
PZC 17	25.00	15.21	46.4
PZC 18	25.00	15.25	50.4
PZC 19	25.00	15.30	55.0
PZC 26	27.88	17.70	73.9

Converting to Metric
If you work in metric, here is the PZC 13¹ converted:

• 50.4 lbs/ft × 1.488 = 75.0 kg/m
• For a 12-meter length: 75.0 × 12 = 900 kg per pile

Why This Matters
The PZC series is designed for efficiency. Notice that PZC 17 through PZC 19 have the same weights as PZC 12 through PZC 14 but with taller sections. This gives you more strength without adding weight. The design allows for lower material costs and fewer piles to install .

I had a client in North America who specified PZC 13¹ for a marine project. He chose it because the 50.4 lbs/ft weight allowed his existing crane to handle the piles without upgrades. The taller section gave him the strength he needed, and the weight kept his equipment costs under control.

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What is the difference between ZZ¹ and AZ sheet piles?

You see these letters in catalogs and wonder if they are the same thing. They are not, and the difference affects your weight calculations and structural design.

ZZ¹ and AZ are both Z-shaped piles, but AZ is a specific product line from ArcelorMittal with optimized interlocks and a range of sizes. ZZ¹ is an older term sometimes used generically for Z piles, but AZ refers to a modern, high-efficiency design with the interlock on the neutral axis for better driving performance .

Breaking Down the Naming Systems

Let me clarify this so you can read catalogs with confidence.

The AZ Series²
AZ piles are a specific brand of hot-rolled Z piles. They feature a special interlock that sits on the neutral axis, even though the pile has a Z shape . This gives you the high strength of a Z profile but protects the interlock from driving stresses. The number in the name usually relates to the section modulus³. A higher number means a stronger pile.

AZ piles come in widths from 630 mm to 700 mm and heights up to 490 mm or more. The WRZ series in some catalogs follows similar principles .

What About ZZ¹?
In some older literature, ZZ¹ refers to Z-shaped piles with double symmetry. But in the modern market, ZZ¹ is often a generic term. The dominant product line from major manufacturers is the AZ series. When you see ZZ¹ today, it might mean any Z pile, but the specifications may vary between suppliers.

The Larssen Connection
Here is an interesting detail. Many AZ piles actually use a variation of the Larssen interlock⁴ system, which was originally developed for U piles . This means the connection is proven and reliable, even though the profile looks different.

Weight Differences
Because AZ piles are optimized for efficiency, they often achieve higher section moduli with lower weights than older Z designs. The WRZ series examples show this clearly:

AZ-Type Section	Width (mm)	Height (mm)	Weight (kg/m)	Section Modulus (cm³/m)
WRZ16-635	635	379	61.5	1610
WRZ18-635	635	380	70.1	1827
WRZ34-675	675	490	118.9	3455

The efficiency comes from putting steel where it works hardest. For the same weight, you get more strength.

My Experience
When a client in Jordan asked for Z piles, I had to ask: do you mean AZ specifically? He did not know. We checked his engineering drawings, and they specified AZ 18. That told me exactly which section to quote. Knowing the difference saved us from ordering the wrong product.

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Conclusion

U type and Z type sheet piles have different weight-to-strength ratios¹, with Z piles generally offering higher efficiency. Always check the manufacturer’s data sheet² for exact weights before ordering.

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