# Sheet stock

Flat sheet identity, explicit thickness and tolerances, finish and condition, usable geometry and fabrication acceptance.

Reviewed: 2026-11-01

Tags: materials, stock-forms, sheet-metal, procurement

## Identify more than the stock form

For **Strenx cold-rolled strip** at **0.80 < t ≤ 1.00 mm**, SSAB's thickness tolerance is **±0.06 mm through 1,200 mm width**, **±0.07 mm above 1,200 through 1,500 mm**, and **±0.08 mm above 1,500 mm**. In the first width band, **1.00 mm nominal** can arrive at **0.94 mm** before any forming or machining. [SSAB cold-rolled strip tolerance table](https://www.ssab.com/en-us/brands-and-products/strenx/guarantee/thickness-flatness-bending)

Sheet stock is flat material supplied for further processing. The word does not establish alloy/grade, condition, thickness tolerance or final-part performance. Use the applicable product standard's definitions rather than applying one universal sheet/plate thickness boundary across metals.

SAE's **J1058_202403** Recommended Practice covers thickness designation and tolerance-specification methods for coated and uncoated hot-rolled/cold-rolled steel sheet and strip. Its publisher record says **stabilized March 2024, reaffirmed April 2015**. It supplies a steel-specific framework, not a dimensional rule for every alloy sold as sheet. [SAE J1058 scope and version](https://saemobilus.sae.org/standards/j1058_202403-standard-sheet-steel-thickness-tolerances)

## Thickness, gauge and units

A gauge number needs its material and gauge convention. For a bounded illustration, McNICHOLS lists its carbon-steel item **16183120** as **20 gauge / 0.0359 inch**, while its Type 304 stainless item **18183120M2** is **20 gauge / 0.0375 inch**. Both are perforated products; the example demonstrates the ambiguity of a bare gauge number, not a universal conversion table for plain sheet. [Carbon-steel item](https://www.mcnichols.com/perforated-metal/round-hole/carbon-steel-cs-16183120), [Type 304 item](https://www.mcnichols.com/perforated-metal/round-hole/stainless-steel-ss-18183120?skuId=18183120M2)

| Field | Meaning to preserve |
| --- | --- |
| Material identity | Grade/alloy, temper or condition, product specification and edition |
| Thickness | Nominal value, unit, tolerance basis and measurement stage |
| Panel geometry | Width, length, squareness, flatness and edge requirements |
| Surface | Finish, coating/film, visible side and acceptance limits |
| Processing evidence | Parent heat/lot, cutting route and required inspection documents |

Nominal dimensions, tolerance limits and actual inspection results serve different purposes. Do not replace a measured result with a catalogue nominal value or infer a guaranteed minimum thickness from a nominal callout.

## A width-dependent tolerance example

SSAB's **Strenx cold-rolled strip** guarantee gives the following thickness deviations for **0.80 < t ≤ 1.00 mm**:

| Nominal width | Published thickness tolerance |
| --- | ---: |
| w ≤ 1200 mm | ±0.06 mm |
| 1200 < w ≤ 1500 mm | ±0.07 mm |
| w > 1500 mm | ±0.08 mm |

These are that named product family's supplier provisions. They are not default tolerances for arbitrary steel, stainless or aluminum sheets. Confirm the actual product, width and contractual requirement. [SSAB thickness guarantee, cold-rolled strip table](https://www.ssab.com/en-us/brands-and-products/strenx/guarantee/thickness-flatness-bending)

## Finish is separate from alloy and condition

Outokumpu's cold-rolled product page distinguishes **2B**, cold rolled/heat treated/pickled/skin passed; **2D**, cold rolled/heat treated/pickled; **2R**, bright annealed; and **2H**, work hardened. Its size availability also differs by finish and product. These supplier descriptions show why “cold rolled” alone does not uniquely establish the supplied state. [Outokumpu cold-rolled coil, strip and sheet](https://www.outokumpu.com/en/products/flat-products/cold-rolled-coil-strip-and-sheet)

Specify the finish and any roughness or appearance requirement that actually controls the part. A finish name does not identify the alloy or establish identical appearance across unrelated lots. Identify visible faces, protective-film requirements and which surfaces may be used as locating datums.

For coated sheet, keep substrate, coating and final-surface requirements separate. Review cutting, welding, forming and cleaning against the selected product's instructions. Neither a coating label nor a bright surface establishes corrosion performance in every environment.

## Usable size and fabrication

A purchased rectangle is not necessarily the usable nesting envelope. Define edge trim, damaged-area exclusions, clamping, cut losses and required rolling-direction orientation. Preserve direction and visible-face identity through cutting where the fabrication plan requires them.

Agree blank dimensions separately from finished-part dimensions. Bending allowance, springback, local thinning and final geometry depend on the material and process; stock form alone supplies no universal bend radius or tool setting. Specify when flatness, squareness, burr and surface acceptance are measured if the blank is later levelled, formed, welded or finished.

## Original mass estimate

Assume a **1000 × 2000 mm** rectangular sheet with **1.00 mm nominal thickness** and an explicitly assumed estimating density of **7850 kg/m³**. Nominal volume is `1.000 × 2.000 × 0.001 = 0.002 m³`; estimated mass is **15.70 kg**.

If only thickness varies over the cited first-row interval, the ideal mass range becomes **14.758–16.642 kg**. This is original arithmetic under constant area/density assumptions, not a supplier's weight guarantee. It excludes coatings, films, dimensional tolerances, cutouts and packaging. Use an applicable density for the actual alloy and distinguish net-metal mass, shipment mass and accepted-part yield.

## Source versions and release record

SAE identifies J1058_202403 as stabilized March 2024. The cited SSAB, Outokumpu and McNICHOLS live pages have no separately verified technical revision date. Their product examples do not establish current inventory or the binding terms of another order.

Retain supplier/producer, heat or lot, material and condition, product specification/edition, explicit dimensions/tolerances, finish, certificate and downstream processing record. Accept the finished component against its own drawing and service requirements. See [Stock forms and dimensions](index.md).