Aluminum Cut-to-Size Tolerance: What Nine Suppliers Actually Publish
By Meriadoc Brandybuck
Two suppliers publish a cut tolerance for aluminum plate: OnlineMetals.com at plus or minus 0.125 inch on long and sheet products, and Speedy Metals at plus or minus 0.030 inch on production sawing orders. Every other supplier we checked publishes nothing. That is the honest state of this industry as of August 2026, and it is why so many shops order oversize by habit and eat the material cost. This post collects every published figure, explains what actually drives saw accuracy, and gives you a rule for how much stock to leave so you stop guessing.
In Short
- →Only two of the nine aluminum suppliers we checked publish a cut tolerance at all.
- →OnlineMetals.com states plus or minus 0.125 inch on long and sheet products. Speedy Metals states plus or minus 0.030 inch on production sawing orders.
- →Alro, Clinton Aluminum, Yarde Metals, Metals Depot, buymetal.com, and McMaster-Carr publish nothing you can plan against.
- →A published tolerance beats an unpublished one even when the unpublished one is tighter, because you can only schedule around a number you have.
- →Practical rule: leave 0.060 to 0.125 inch of facing stock per cut face on a sawn edge, more if the supplier will not commit to a number.
- →Never design a sawn edge as a finished or reference surface. Saw cuts are stock removal operations, not finishing operations.
Every Published Cut Tolerance We Could Find
Checked against public pages in August 2026. Unpublished means the supplier does not state a figure, not that their cuts are inaccurate. It means you cannot plan around it without asking.
| Supplier | Published cut tolerance | Where it applies |
|---|---|---|
| Speedy Metals | Plus or minus 0.030 inch | Production sawing orders |
| OnlineMetals.com | Plus or minus 0.125 inch | Long and sheet products, unless specified |
| Clinton Aluminum | Unpublished | Precision shearing referenced, specs by link |
| Alro Steel | Unpublished | Saw, CNC saw, waterjet, laser, plasma |
| Yarde Metals | Unpublished | Cutting offered on request |
| Metals Depot | Unpublished | Cut to size and custom shapes |
| buymetal.com | Unpublished | Standard or cut to size |
| McMaster-Carr | Not applicable | Standard stock sizes |
| NOX METALS | Ask for your thickness | Bandsaw, 0.08 inch kerf |
Why the Range Is So Wide
The spread between 0.030 and 0.125 inch is not a quality gap between companies, it is mostly a difference in equipment and in what is being cut. Understanding the drivers tells you which number to trust for your part.
- Thickness. A saw blade wanders more through 4 inches of 7075 than through 0.5 inch of 6061. Deflection accumulates over the depth of cut.
- Blade and feed. Blade condition, tooth pitch, and feed rate drive both accuracy and finish. A production saw pushing volume runs different parameters than a saw set up for a single accurate cut.
- Kerf. Every saw removes material as it cuts. Our bandsaws run a 0.08 inch kerf, which is material that has to be accounted for in the layout, not in the tolerance.
- Material stress. Plate that has internal stress can move as it is cut, especially in thick 7000-series sections. That is a metallurgy problem, not a saw problem, and it is why stress-relieved tempers exist.
- Squareness versus length. Length tolerance and squareness are different specifications. A cut can be dead on length and still be out of square, and most published figures only address length.
How Much Facing Stock to Leave
This is the number you actually need. It assumes you are machining the part after receiving it, which you almost always are on a sawn edge.
| Situation | Stock to leave per cut face | Why |
|---|---|---|
| Supplier publishes plus or minus 0.030 inch | 0.060 inch | Covers the tolerance band plus a cleanup pass |
| Supplier publishes plus or minus 0.125 inch | 0.160 inch | Covers an eighth of an inch of variance plus cleanup |
| Supplier publishes nothing | 0.125 to 0.250 inch | You are guessing, so guess generously |
| Thick section, 3 inches and up | Add 0.060 inch | Blade deflection grows with depth of cut |
| 7000-series, stress sensitive | Add 0.060 inch | Material can move as it is cut |
| Sawn edge used as a datum | Do not | Reface it. A saw cut is not a reference surface |
The Question That Gets You a Real Answer
Suppliers who do not publish a tolerance will usually tell you if you ask correctly. The trick is asking about your part rather than about their capability in general.
- What length tolerance will you hold on a 3 inch thick 7075 plate cut to 14 inches? Naming the thickness and the alloy gets a specific answer.
- What squareness can you hold on that cut? This is a separate number from length and it is the one that surprises people.
- Is that tolerance a commitment or a typical result? A typical result is not something you can plan a fixture around.
- What is your kerf, and is the dimension I give you the finished size or the layout size?
- If the cut comes in under tolerance, what is the remedy? Ask before, not after.
When Cut-to-Size Is the Wrong Choice
Sometimes the honest answer is not to buy cut to size at all, and no supplier will volunteer this.
- If the finished part needs tight tolerances on all six faces, you are machining all six anyway. Buy oversize at the best price per pound and stop paying for a cut you are going to remove.
- If the part is tiny relative to available stock, a drop or remnant is usually cheaper than a cut, and it ships faster because no sawing is needed.
- If you need a profile rather than a rectangle, a saw is the wrong tool. Waterjet or laser, and Alro offers both.
- If you need plus or minus 0.005 inch on a dimension, no saw will do it. That is a milling operation, and asking a supplier for it will get you a no or a very expensive yes.
Two published numbers across nine suppliers is not much to work with, and it is the reason so many shops default to ordering oversize. If your supplier publishes a tolerance, plan facing stock around it. If they do not, ask about your specific thickness and alloy and get the answer in writing, then add margin. And never design a sawn edge as a finished surface, regardless of what number anyone gives you.
Frequently Asked Questions
What is a typical cut tolerance for aluminum plate?
Published figures range from plus or minus 0.030 inch on production sawing at Speedy Metals to plus or minus 0.125 inch on long and sheet products at OnlineMetals.com. Most suppliers publish nothing. Plan on plus or minus 0.060 inch or worse on a sawn edge unless you have a written commitment.
How much material should I leave for facing on a cut-to-size plate?
Leave roughly twice the published tolerance per cut face, so 0.060 inch against a plus or minus 0.030 inch commitment and about 0.160 inch against plus or minus 0.125 inch. Add another 0.060 inch for thick sections above 3 inches and for stress-sensitive 7000-series material.
Can I use a sawn edge as a reference surface?
No. A saw cut is a stock removal operation, not a finishing operation, and the edge will not be flat, square, or repeatable enough to serve as a datum. Face it before you use it as a reference.
Why does thickness affect cut accuracy?
A saw blade deflects over the depth of the cut, and the deflection accumulates. Cutting 4 inches of 7075 gives the blade far more opportunity to wander than cutting 0.5 inch of 6061. Internal stress in thick 7000-series plate can also cause the material to move as it is cut.
What is kerf and does it come out of my dimension?
Kerf is the material the blade removes as it cuts. Our bandsaws run a 0.08 inch kerf. Kerf is a layout consideration rather than a tolerance, but you should always confirm with any supplier whether the dimension you give them is the finished size or the layout size.
Know before you cut
Ask us for the tolerance on your thickness.
Configure your plate and get a price, a ship date, and a straight answer on what the saw will hold for your specific alloy and thickness.