Standard blank sizes for CNC machining (sheets & rods)
Tables of the standard blank sizes (sheets & rods) commonly used in CNC machining.
Introduction
The “blank” in CNC machining is the piece of material (metal or plastic) that is initially loaded to the machine. Stock materials come as plates (for CNC milling) or rods (for CNC turning) in a variety of sizes. In the tables below we summarize the most common blank dimensions found in a typical machine shop.
Note: 0.3 mm to 1.5 mm of material will be removed from each side of the blank during machining (that is up to 3 mm total). This should be taken into account during design as the blank size can significantly increase the material cost for large-scale productions.
Plates
Stock plates come pre-cut to size or as large sheet (typically, 2 m by 1 m - 6 ft. by 3 ft.) that are cut to blanks by the machine shop. So, the limiting dimension for a plate when it comes to design is its thickness.
The table below summarizes the most common aluminum and steel plate thicknesses that can be found in the warehouse of every machine shop. For an extensive, refer to a material supplier catalog.
| Thickness [mm] | Thickness [inches] |
|---|---|
| 3 mm | 3/16'' |
| 4 mm | 1/4'' |
| 5 mm | 5/16'' |
| 6 mm | 3/8'' |
| 8 mm | 7/16'' |
| 10 mm | 1/2'' |
| 12 mm | 5/8'' |
| 15 mm | 3/4'' |
| 20 mm | 1'' |
| 25 mm | 1/2'' increase therafter (up to 5'') |
| 30 mm | |
| 10 mm increase thereafter (up to 100 mm) |
Rods
Rods come as long stock (typically, 1 m - 3 ft. - or longer) that are cut to blanks by the machine shop. The limiting dimension here is the diameter of the rod.
The table below summarizes the most common aluminum and steel plate thicknesses that can be found in the warehouse of every machine shop. For an extensive, refer to a material supplier catalog.
| Diameter [mm] | Diameter [inches] |
|---|---|
| 3 mm | 1/8'' |
| 4 mm | 3/16'' |
| 5 mm | 1/4'' |
| 6 mm | 5/16'' |
| 7 mm | 3/8'' |
| 8 mm | 7/16'' |
| 9 mm | 1/2'' |
| 10 mm | 5/8'' |
| 12 mm | 3/4'' |
| 14 mm | 7/8'' |
| 15 mm | 1'' |
| 16 mm | 1/4'' increase therafter (up to 3'') |
| 20 mm | |
| 25 mm | |
| 30 mm | |
| 40 mm | |
| 10 mm increase therafter (up to 100 mm) |
More resources for engineers
Understanding material stress vs. strain
Read article
What are countersinking holes and how do you use them?
Read article
Understanding tapped vs. rolled threads
Read article
Rz vs Ra roughness
Read article
Different types of quality documentation and when you need them
Read article
How do you deal with sharp corners in CNC machining? Designing with the machinist in mind
Read article
What is GD&T? How to reduce manufacturing errors and improve quality
Read article
What is design for manufacturability (DFM)?
Read article
What is anodizing and how does it work?
Read article
What are the different types of threads for manufacturing? Practical tips for engineers
Read article
Standard blank sizes for CNC machining (sheets & rods)
Read article
What is subtractive manufacturing?
Learn how subtractive manufacturing shapes parts by removing material. Explore CNC, drilling, laser cutting, and how it compares to additive methods.
Read article
Understanding material stress vs. strain
“Can you handle the pressure?” That’s the question engineers have to ask of every material they consider when they are designing for manufacturability. Stress and strain are fundamentals of material science, helping engineers assess how materials hold up under different forces. Read on to find out how they are measured.
Read article
What are countersinking holes and how do you use them?
Countersinking holes are conical holes designed to seat the head of a screw, bolt, or fastener so it sits flush with or just below the surface. This keeps the part’s outer layer smooth, which can improve its appearance, safety and performance. In this guide, we’ll drill into the ins and outs of countersinking, covering methods, applications, pros and cons, and tips for getting it just right.
Read article
Understanding tapped vs. rolled threads
What are tapped and rolled threads, and what do engineers need to know about them to manufacture high-performance parts? Find out here.
Read article
Rz vs Ra roughness
Rz and Ra are measurements used to describe and quantify surface roughness in manufacturing and engineering. Find out more about these different ways of measuring roughness as a machining finish for custom parts.
Read article
Different types of quality documentation and when you need them
Learn about the role quality documentation plays in the manufacturing process, how to obtain it, and the types of documentation that apply to parts, materials, and more
Read article
How do you deal with sharp corners in CNC machining? Designing with the machinist in mind
Have you designed your parts with sharp corners? They may look good on paper, but they're a nightmare to manufacture with CNC machining. In this article, learn how and why to avoid sharp corners in your designs. It'll reduce lead times, cost and potential headaches for machinists.
Read article
What is GD&T? How to reduce manufacturing errors and improve quality
What is Geometric Dimensioning and Tolerancing (GD&T) and how is it used? This article explores the basics of how and when to use GD&T to get the best results out of custom part manufacturing.
Read article
What is design for manufacturability (DFM)?
Design for manufacturing (DFM) means taking a design-first approach to manufacturing. In this article, we look at the overall DFM process, the necessary steps for a successful outcome, examples of DFM done right and how to get the most out of your own processes.
Read article
What is anodizing and how does it work?
What is anodizing? Anodizing is key to finishing parts made from aluminum and other metals. Learn how anodizing works and why it is an important part of CNC machining and manufacturing.
Read article
What are the different types of threads for manufacturing? Practical tips for engineers
What are the different types of threads for manufacturing? In this article, learn how to correctly design threads to reduce lead times and cost for your next CNC machining production run.
Read article
Standard blank sizes for CNC machining (sheets & rods)
Tables of the standard blank sizes (sheets & rods) commonly used in CNC machining.
Read article