Most cantilever racks ship with uniform arm spacing — every level set to the same fixed height, regardless of what you’re actually storing. If your shop carries a mix of heavy round pipe, angle iron, and flat bar, that one-size-fits-all design is quietly costing you 30–40% of your vertical storage capacity. The fix is simpler than most buyers realize: specify the actual height of each material type before you order, and have each arm level configured to match. CK Metal Storage does this for every order, at no extra charge.

 

The Problem Nobody Talks About When Buying a Cantilever Rack

If you’re shopping for a cantilever rack to store steel profiles — round tube, angle iron, flat bar, square bar — you’ve probably been comparing load capacity, arm length, and price. That’s the right starting point.

But there’s one spec almost nobody asks about: the vertical spacing between arm levels.

Here’s why it matters more than most buyers expect.

Steel profiles come in very different heights. A bundle of 6-inch round pipe sits about 7–8 inches tall on a rack arm. A stack of 2×2 angle iron? Maybe 4 inches. Flat bar? As little as 1.5 to 2 inches per stack. The height difference between your heaviest pipe and your smallest flat bar can easily be 5 to 6 inches per level.

Now picture a standard cantilever rack with uniform 12-inch arm spacing across all 5 levels. Your heavy pipe fits fine. But on the levels holding flat bar or small angle iron, you’ve got 8 to 10 inches of empty air above each layer of material. You paid for that space. You’re just not using it.

Across a rack with 5 levels and a 4-meter upright, that dead airspace can add up to 40% of your total vertical capacity — gone.

Why Standard Racks Are Built This Way

Standard cantilever racks are manufactured in fixed configurations — typically with arm levels spaced 12 to 16 inches apart — because it simplifies production. One upright design, one column punch pattern, one SKU. It works for buyers who store a single material type. It doesn’t work well for fabrication shops, steel service centers, or laser cutting operations that carry 3 to 6 different profile types at the same time.

The industry has historically treated this as an acceptable trade-off. The assumption is that buyers will just leave the empty space, or double-stack materials and deal with the safety and access problems that come with that.

Neither option is great.

 

What Custom Arm Spacing Actually Looks Like

The concept is straightforward: before manufacturing, a supplier measures or asks about the actual stacked height of each material type you plan to store, then configures each arm level to leave just enough clearance above the material for safe loading and unloading — typically 2 to 3 inches of clearance, no more.

Here’s a simple example of how the numbers work out:

Material Type	Typical Stack Height	Clearance Needed	Level Height Required
6″ round pipe (bundle)	7–8 in / 18–20 cm	2–3 in / 5–8 cm	~10–11 in / 25–28 cm
4×4 angle iron	4–5 in / 10–13 cm	2–3 in / 5–8 cm	~7 in / 18 cm
Flat bar (2″)	1.5–2 in / 4–5 cm	2–3 in / 5–8 cm	~5 in / 13 cm
Square bar (1″)	1–1.5 in / 3–4 cm	2–3 in / 5–8 cm	~4–5 in / 10–13 cm

On a rack with a standard uniform 12-inch arm spacing, those four material types would use an average of just 7 inches of every 12-inch level — a 42% waste rate.

With custom arm spacing matched to each material, you can fit more levels on the same upright height, or store more material per level without changing your footprint at all.

How CK Metal Storage Handles This

Before CK Metal Storage builds a cantilever rack, we ask one question most suppliers skip: What are you actually storing on each level?

Round tube? Angle iron? Flat bar? Long bar stock? What’s the cross-section height of the material you’ll be loading?

Once we have that information, we configure every arm level individually — tall levels for your heavy pipe and tubing, tighter levels for your smaller profiles and flat bar. The result is a rack where every level fits like it was designed for your shop. Because it was.

This customization is included in the standard order process. There’s no engineering surcharge, no minimum order for custom configurations.

Same floor space. More storage. Zero extra charge.

Standard vs. Custom: It’s Not Just About Space — It’s About Your Timeline Too

To be straightforward about this: standard racks and custom-configured racks each have a real advantage, and the right choice depends on your situation.

Standard fixed-spacing racks are built in advance and held in inventory. That means faster lead times — in many cases, a standard unit can ship within days of order confirmation. If you need a rack up and running quickly, or you’re storing a single material type where uniform spacing works fine, a standard rack is a perfectly reasonable choice.

Custom arm-spacing racks are built to order based on your specific material profile mix. That means a longer production lead time — typically a few additional weeks compared to an in-stock standard unit. The payoff is a rack that’s optimized for exactly what you’re storing, recovering 25–40% of vertical capacity that a standard rack would leave unused.

Here’s a simple way to think about it:

	Standard Rack	Custom Arm-Spacing Rack
Lead time	Short — often ships from stock	Longer — built to order
Best for	Single material type, urgent timeline	Mixed profiles, maximizing warehouse space
Arm spacing	Fixed, uniform across all levels	Configured per level to match your materials
Cost	Standard pricing	Same pricing — no custom surcharge at CK
Space efficiency	Good for uniform loads	Up to 40% better for mixed-height profiles

The honest answer is: if you need the rack next week, a standard unit is probably your best option. If you’re planning ahead and your shop carries 3 or more different profile types, it’s worth the extra lead time to get something that actually fits your inventory.

The mistake to avoid is assuming custom always means more expensive, or that standard is always “good enough.” Ask the question before you commit.

 

What to Ask Any Supplier Before You Buy

Whether you’re buying from CK Metal Storage or anyone else, here are the questions worth asking during the inquiry process:

1. Is arm level spacing fixed or configurable? Many suppliers offer adjustable arms (you can move the arm up and down in the column after delivery), but that’s different from pre-configuring the optimal spacing before manufacturing. Ask specifically about the vertical distance between arm levels.
2. What’s the standard arm spacing on your racks? If the answer is a single number — “12 inches” or “400mm” — and they’re not asking what you’re storing, that’s a sign you’re getting a standard-production unit.
3. Can you match arm spacing to my material stack heights at no extra cost? This is the key question. Some suppliers can do it, but charge a custom manufacturing fee. Others build to order by default. Know which kind you’re dealing with before you get to contract.
4. What’s the clearance above the top level? The top arm level is often overlooked. If your tallest material and the top clearance aren’t accounted for, you may not be able to load the top level safely with a crane or forklift.

 

FAQ

What is standard cantilever rack arm spacing? Most off-the-shelf cantilever racks use arm spacing between 12 and 16 inches (300–400mm) per level, with all levels set to the same height. This works well for single-material storage but creates significant wasted space in mixed-material applications.

Can I adjust arm spacing after the rack is installed? It depends on the rack design. Some cantilever systems use adjustable arms that can be repositioned along the column after installation. However, the column hole pattern limits how granular the adjustment can be. Pre-configuring spacing before manufacturing gives more precise results.

How much vertical space can custom arm spacing save? In a typical mixed-profile application — storing pipe, angle iron, and flat bar on the same rack — custom arm spacing can recover 25–40% of vertical capacity compared to a standard uniform-spacing configuration. The actual savings depend on the height range of materials you store.

Does custom arm spacing cost more? It depends on the supplier. Some manufacturers charge a custom configuration fee. CK Metal Storage includes arm-level customization as part of the standard order process at no additional charge.

What information do I need to provide to get custom arm spacing? At minimum: the types of material you’ll be storing on each level, the cross-section height of each material type when stacked (or a bundle diameter for round stock), and the number of levels you need. A simple list or even a photo of your current storage situation is usually enough to get started.

Does custom arm spacing take longer to deliver than a standard rack? Yes, typically. Standard cantilever racks are manufactured in fixed configurations and held in inventory, so they can often ship within days of order confirmation. Custom arm-spacing racks are built to order and require additional production time — usually a few extra weeks. If your timeline is tight, discuss lead times upfront with your supplier. If you have flexibility, the wait is generally worth it for a mixed-profile storage application.

Is a cantilever rack with custom arm spacing harder to reconfigure later? Not necessarily. The arms themselves are still the same standard components — only the positioning of the arm attachment points on the column changes. If your material mix changes significantly in the future, most reputable suppliers can provide replacement uprights or supplementary columns to accommodate.

 

CK Metal Storage manufactures custom cantilever racks and steel profile storage systems for fabrication shops, laser cutting operations, and steel service centers worldwide. To discuss arm spacing configuration for your application, contact our team.