# MIC-6 cast aluminum tooling plate

Producer-associated MIC6 plate identity, published stock tolerances and typical properties, with limits for machining, finishing and fixture qualification.

Reviewed: 2026-11-01

Tags: materials, aluminum, producer-products

## Product identity and purchasing boundary

Alcoa's archived **MIC6** brochure gives maximum flatness deviation of **0.015 in (0.381 mm)** for **¼–⅝ in** stock and **0.005 in (0.127 mm)** for **¾ in and thicker**. The limits cover mill plate and properly cut blanks measured on a flatness table with a straightedge up to **8 ft**. Specify the finished fixture's support, mounting and temperature for a separate flatness check. [Alcoa archived mill-plate brochure](https://www.yarde.com/pdf_download.php?file=mic-6_brochure.pdf)

**MIC6 is a producer-associated cast aluminum plate product; it is not a generic designation for every cast tooling plate.** Arconic's 2023 Sustainability Report identifies MIC 6 Precision Machined Cast Aluminum Plate in its industrial-products portfolio, emphasizing flatness, dimensional stability and tolerance control during machining. That establishes product identity, not a current purchasing specification or certification of a supplied blank. [Arconic, 2023 Sustainability Report, p. 14](https://arconic.com/documents/d/arconic/2023-sustainability-report)

## What the producer literature establishes

Alcoa's archived MIC6 brochure describes near-net-thickness casting, granular structure and a separate thermal stress-relief treatment. Its published stock limits include:

| Characteristic | Published limit |
|---|---|
| Thickness | ±0.005 in (±0.127 mm) |
| Flatness, 1/4–5/8 in plate | Maximum deviation 0.015 in (0.381 mm) |
| Flatness, 3/4 in and thicker | Maximum deviation 0.005 in (0.127 mm) |
| Surface | Both faces machined; maximum 20 microinch or 0.50 µm smoothness |

Flatness applies to mill plate and properly cut blanks under the stated measuring conditions, including a flatness table and straightedge up to eight feet long. [Alcoa, MIC6 producer brochure, hosted by Yarde Metals](https://www.yarde.com/pdf_download.php?file=mic-6_brochure.pdf)

The **±0.005 in thickness tolerance** controls size. Flatness is the maximum departure measured under the stated conditions.

TCI's technical explanation distinguishes flatness of one surface from parallelism relative to a datum surface or line. Accordingly, specify the finished part's flatness, thickness, parallelism and datum relationships separately. A good surface finish also cannot substitute for any of those geometric requirements. [TCI Precision Metals, Understanding Parallelism and Flatness](https://tciprecision.com/ready-to-ship-blanks/understanding-parallelism-and-flatness/)

## Typical properties and thermal movement

The Alcoa brochure reports typical tensile strength of 24 ksi/166 MPa, yield strength of 15 ksi/105 MPa, elongation of 3%, and modulus of 71,000 MPa. Its average expansion coefficient is 23.6 × 10⁻⁶/K over 20–100°C. [Alcoa, specifications table](https://www.yarde.com/pdf_download.php?file=mic-6_brochure.pdf)

Treat typical values as screening information, not lot-specific acceptance minima, fatigue allowables or a structural qualification. The printed rounded ksi/MPa pairs should remain labeled as published values rather than being represented as exact unit conversions.

**Calculated illustration:** assuming uniform free expansion over the stated interval, a 500 mm length heated from 20 to 80°C changes by:

`ΔL = α × L × ΔT = 23.6 × 10⁻⁶/K × 500 mm × 60 K = 0.708 mm`.

This predicts free length change, not bow, mounting stress or positional accuracy. A thermally stabilized plate can still expand. A fixture drawing must resolve differential movement of its base, workpiece, inserts and locating elements before assigning a temperature-dependent accuracy requirement.

## Machining and finishing decisions

Alcoa recommends sharp tools, suitable cutting fluids, supported sawing and removing residual coolant. It describes anodizing with possible shade/texture variation, and welding with procedure qualification on mockups. It warns against marine exposure. [Alcoa, machining and working guidance](https://www.yarde.com/pdf_download.php?file=mic-6_brochure.pdf)

Use those as boundaries for process planning. Qualify the actual pocketing pattern, remaining wall thickness, support and clamping arrangement. Stock stability does not certify a heavily relieved component's final geometry. Inspect after unclamping and after the agreed finishing/conditioning sequence, with the inspection support condition documented.

For anodized appearance, agree an acceptable sample and the surfaces to be evaluated before production. For a welded assembly, establish the welding procedure, filler selection, distortion allowance and final inspection through the responsible welding specification and product guidance. Neither “cannot be welded” nor “weldable without consequences” is an adequate drawing note.

For threads and repeatedly loaded locating features, specify required engagement, allowable load and service cycles. Select inserts or replaceable wear details through the fixture design rather than inferring their capacity from the plate's tensile strength.

## Processed blank versus mill plate

TCI's **DB-MIC6-1000-06-12** is a named 1 × 6 × 12 in, four-side precision blank. Its specific description retains stock thickness while specifying width and length milling to ±0.002 in. That is a processor's product offering, not a new universal mill tolerance for MIC6. Confirm the controlled dimensions and any conflicting general catalog wording in the order acknowledgement. [TCI, named MIC6 blank](https://tciprecision.com/product/db-mic6-1000-06-12/)

For example, buying this processed blank does not by itself establish a finished pocket depth, hole position or flatness after machining. Match each acceptance requirement to the operation that creates it and the inspection that verifies it.

## A finished fixture example

Carr Lane's **CL-1214-00-CLFP** uses precision-machined MIC-6 cast aluminum in a 12 × 14 × 0.750 in fixture plate, with four locating/mounting holes for its 20 mm Carr Lock clamps. Carr Lane separately specifies receiver-hole location, clamp repeatability, bushing concentricity and resulting mounted-system x/y repeatability, including tolerance accumulation. These are fixture-system specifications, not bulk-material properties. [Carr Lane, Carr Lock fixture plate](https://www.carrlane.com/product/carr-lock-system/carr-lock-fixture-plates/carr-lock-fixture-plates/carr-lock-fixture-plates-12-x-14)

Measure fixture performance with the specified locating hardware, mating base and mounting procedure.

## Source status and release record

The cited Alcoa document is archived producer literature distributed by Yarde Metals. Its file title includes “rev 2012,” but an explicit publication/revision date was not verified; that title and the hosting date are not treated as a current specification date. Arconic's cited report covers **2023**. The live TCI and Carr Lane pages display no technical revision date.

Before release, obtain the current supplier acknowledgement for the exact plate or processed blank. Preserve product traceability, stock and finished tolerances, inspection support/temperature, any finish sample and agreed documentation. This draft does not establish a chemistry equivalence, universal service temperature, pressure-vessel suitability or customer-specific approval.

[Grades, conditions and material selection](../grades-tempers-and-conditions.md)