Where to Buy Cast Tool and Jig Plate: MIC-6, ATP-5, Alca5, and K100-S Explained
By Bilbo Baggins
MIC-6, ATP-5, Alca5, K100-S, QC-10, and Max-5 are trade names for the same category of product: cast aluminum tool and jig plate, produced by different mills, and largely interchangeable for most fixture work. Buyers routinely spend time hunting for a specific trade name when what they actually need is a thickness tolerance and a flatness spec that several of them meet. This post explains the equivalence, what specifications actually matter, which suppliers stock which names, and the one substitution you should never make.
In Short
- →MIC-6, ATP-5, Alca5, K100, K100-S, QC-10, and Max-5 are trade names for cast tool and jig aluminum plate from different producers. They are largely equivalent products.
- →You are buying flatness and dimensional stability, not strength. Cast tooling plate is chosen because it does not move, not because it is strong.
- →Typical cast tooling plate is machined both sides to a thickness tolerance around plus or minus 0.005 inch with a surface finish around 20 RMS or better, usually with PVC protective film.
- →Yarde Metals lists the widest set of trade names. Clinton Aluminum leads with ATP-5. OnlineMetals, Speedy Metals, buymetal.com, and Alro all carry cast tooling plate.
- →Do not substitute 6061-T651 for cast tooling plate on a fixture that needs to hold flatness. Rolled plate carries residual stress and will move as you machine it.
- →Compare thickness tolerance, flatness spec, and surface finish. Ignore which trade name the supplier happens to stock.
The Trade Names, and Who Stocks Them
Verified against public pages in August 2026. The point of this table is that the name in the left column is rarely the thing to optimize for.
| Supplier | Cast tool and jig names listed |
|---|---|
| Yarde Metals | ALCA-5, K100, K100-S, MIC-6, QC-10, QC-7, M-1, M-5, MAX-5 |
| Clinton Aluminum | ATP-5, plus 5000-series CT&J and mold plate lines |
| NOX METALS | Cast tool and jig plate, cut to size with certs |
| OnlineMetals.com | MIC-6 cast tooling plate, precision milled blanks |
| Speedy Metals | Cast tool and jig |
| buymetal.com | Cast tooling plate |
| Alro Steel | Aluminum cast tool and jig plate |
| Metals Depot | Unpublished |
| McMaster-Carr | Cast tooling plate in catalog sizes |
What You Are Actually Buying
Cast tooling plate is a fundamentally different product from rolled plate, and the reason to pay more for it has nothing to do with strength.
- It is cast, not rolled. Rolling imparts directionality and residual stress. Casting does not, which is why cast plate stays flat when you machine into it.
- It is machined on both faces at the mill, typically to a thickness tolerance around plus or minus 0.005 inch, with a surface finish commonly quoted at 20 RMS or better.
- It ships with PVC protective film on both faces, which is there to protect the finish you paid for. Leave it on until the part is set up.
- It is weaker than 6061-T651 in tensile strength and considerably weaker than 7075. If your part is structural, cast tooling plate is the wrong material.
- It typically machines cleanly and predictably, which is a real advantage on large fixture plates with many features.
The Substitution That Ruins Fixtures
The most common and most expensive mistake in this category is substituting rolled 6061-T651 for cast tooling plate to save money on a fixture.
- Rolled plate carries residual stress from rolling and quenching. Machining a large pocket into one side unbalances that stress and the plate bows.
- On a small bracket this does not matter. On a 24 by 36 inch vacuum table or a large inspection fixture, it absolutely does, and you discover it after the machining time is spent.
- T651 is stress relieved by stretching, which helps substantially, but it is still rolled plate and it is still directional.
- If the requirement is that the surface stays flat after you machine it, buy cast. If the requirement is that the part carries load, buy 6061-T651 or 7075.
- Our aluminum plate warp calculator and tooling plate selector both address this decision directly.
What to Compare Instead of Trade Names
Four specifications decide whether a plate works for your fixture. Ask for all four in writing and the trade name becomes irrelevant.
- Thickness tolerance. Commonly around plus or minus 0.005 inch on cast tooling plate. Confirm it, because it varies by producer and thickness.
- Flatness specification, stated over a defined length. This is the number that actually matters on a large plate and the one most often omitted.
- Surface finish, typically quoted in RMS. 20 RMS or better is the common benchmark.
- Thickness availability in your size, and whether both faces are machined. Some products are machined one side only.
Where to Buy, by Situation
- You need an unusual trade name because a customer print specifies it: Yarde Metals lists the widest set.
- You need ATP-5 specifically or a large mold plate program: Clinton Aluminum is the specialist and describes itself as North America's largest aluminum mold plate distributor.
- You need a small MIC-6 blank for a one-off fixture: OnlineMetals sells precision milled blanks with no minimum.
- You need cast tool and jig cut to size with mill certs and a committed ship date: us.
- You need it tomorrow in a standard size: check McMaster's catalog first.
Cast tool and jig plate is one product category wearing seven trade names, and comparing names rather than specifications wastes time and occasionally money. Decide on thickness tolerance, flatness over your actual dimension, and surface finish, then buy whichever equivalent product your supplier stocks. And do not substitute rolled plate on a fixture that has to stay flat, because that saving disappears the first time a plate bows after machining.
Frequently Asked Questions
Is MIC-6 the same as ATP-5?
They are largely equivalent cast aluminum tool and jig plates from different producers, as are Alca5, K100-S, QC-10, and Max-5. All are precision machined cast plate chosen for dimensional stability and flatness. Compare thickness tolerance, flatness spec, and surface finish rather than the trade name.
What is cast tool and jig plate used for?
Fixtures, jigs, inspection plates, vacuum and router tables, mold bases, patterns, and automation baseplates. Anything where the plate must stay flat and dimensionally stable after machining. It is not a structural material.
Can I use 6061 instead of MIC-6?
For a small bracket, usually yes. For a large fixture that must stay flat, no. Rolled 6061 carries residual stress and will move when you machine features into one side. Cast tooling plate exists specifically to avoid that, and the failure shows up after you have spent the machining time.
What tolerance does cast tooling plate hold?
Thickness tolerance is commonly around plus or minus 0.005 inch with a surface finish of about 20 RMS or better, machined on both faces and shipped with PVC film. Flatness varies with size and producer, so ask for the flatness spec over your actual plate dimension in writing.
Is cast tooling plate stronger than 6061?
No. It is weaker in tensile strength than 6061-T651 and considerably weaker than 7075. You buy it for dimensional stability and flatness, not strength. If the part carries load, specify a rolled structural alloy instead.
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