Find the Right Shank Code for Your Hardware (Updated for 2024)

Last updated on January 23rd, 2024 at 12:00 pm

Do you know which self-clinching PEM® nut has the correct shank code for your precision fabrication project?

In most of the sheet metal forming world, and here at Approved Sheet Metal, PEM® hardware is the go-to choice for self-clinching nuts. A common alternative to welding, self-clinching nuts are specialized internally threaded fasteners that provide many benefits, including increased thread strength.

When self-clinching nuts are inserted and pressed into a mounting hole in a workpiece, they displace the host material, forcing it to “cold flow” into a recess in the shank. The self-clinching nut then locks into position and becomes a permanent part of the workpiece.

Why Shank Size Matters

Shanks play an essential role in self-clinching nuts, and engineers need to choose hardware with the correct shank size for their parts to function as intended.

Shank size must be relative to material thickness.

• If the shank is too thick for the material, the hardware will stick out when the machine presses the self-clinching nut into the metal.
• If the material is thick and the shank is too thin, the self-clinching nut won’t grip the material with enough strength, and the workpiece won’t be secure.

When choosing self-clinching PEM® nuts, the length code

indicates the length of the shank. However, many engineers aren’t sure which shank code they need for their parts, causing them to select the wrong hardware for their project.

How to Select the Shank Code for Your Precision Fabrication

Shank codes are numbered 0 (if not applicable), 1, 2, or 3. Knowing which one will suit your project best can be challenging.

We’re experts at hardware selection at Approved Sheet Metal and frequently help our customers choose hardware for their sheet metal forming projects. But! We also want to empower YOU to select the proper hardware for your precision sheet metal parts.

We’ve created a handy guide that can help you identify the right shank code for your precision fabrication project.

Here’s how to use this sheet metal hardware chart:

1. Identify your hardware type. Find the style of self-clinching PEM® nuts you want for your part, listed in red. If you’re struggling to select a hardware type, this refresher from PEM® might make it easier:

• S/SS nuts are recommended for use in steel or aluminum sheets HRB 80 / HB 150 or less.
• CLS or CLSS nuts are recommended for use in steel or aluminum sheets HRB 70 / HB 125 or less.
• SP nuts are recommended for use in stainless steel sheets HRB 90 / HB 192 or less.
• CLA nuts are recommended for use in steel or aluminum sheets HRB 50 / HB 82 or less.

2. Choose the corresponding thread code. We’ve provided thread codes in standard and metric for your convenience.

3. Find the accompanying minimum sheet thickness of your material.

4. Note the shank code that aligns with your factors: hardware type, thread code, and sheet thickness.

For example, if your material is 0.040″ thick and you want an M3 nut, which shank code do you choose? Answer: 1! If your material is 0.074″ thick and you want an M3 nut, you’d select a 2.

How to Use Shank Codes to Choose the Right PEM® Nuts

Once you know which shank code you need for your custom sheet metal parts, you’ll be able to pick the correct self-clinching PEM® nuts.

All PEM® self-clinching nuts have part numbers, and strings of codes representing this information:

• Type: S, SS, CL, CLS, S, or CL
• Material Code: S, P, or A
• Thread Size Code: Can vary; 256, 348, 440, 632, etc.
• Shank Code: 0, 1, 2, 3 (zero indicates no shank)
• Finish: Can vary; Z1, CU, etc., or blank if not applicable

The part numbers follow this formula: Type and Material Code-Thread Code-Shank Code and Finish

For example, the part number CLA-632-2 can be broken down like this:

• Type: CL
• Material Code: A
• Thread Size Code: 632
• Shank Code: 2
• Finish: None

Let’s look at another one. The part number CLS-440-1 can be broken down like this:

• Type: CL
• Material Code: S
• Thread Size: 440
• Shank Code: 1
• Finish: None

Now you’re ready to select the proper hardware for your precision fabrication projects every time!  However, as always, our team is more than happy to assist you, so if you want an expert opinion to ensure the success of your parts, just ask.

Request a quote to get started with Approved Sheet Metal today.

Sheet Metal Hardware Hole Sizes Chart

CHART DOWNLOAD

Hardware hole sizes are the number one thing sheet metal fabricators have to fix before sending a part to the floor. So we have created a referenceable chart for product developers that are designing sheet metal parts. Use this chart to find the correct hole size for the hardware you select.

Get it now

Sheet Metal Hardware Shank Code FAQ

How do I select the right shank code for my precision fabrication project?

Selecting the right shank code involves considering factors like hardware type, thread code, and sheet thickness. Start by identifying your desired self-clinching PEM® nut style based on material type and thickness. Then, choose the corresponding thread code and find the minimum sheet thickness for your material. The shank code that aligns with these factors is the one you should select. A guide provided by Approved Sheet Metal can help simplify this process.

What are self-clinching PEM® nuts and how do they work?

Self-clinching PEM® nuts are specialized internally threaded fasteners commonly used in sheet metal fabrication. When inserted and pressed into a mounting hole in a workpiece, they displace the host material, causing it to “cold flow” into a recess in the shank of the nut. This locking mechanism makes the self-clinching nut a permanent part of the workpiece, providing increased thread strength and eliminating the need for welding.

What is the significance of part numbers in self-clinching PEM® nuts?

Part numbers in self-clinching PEM® nuts carry essential information about the nut’s specifications. The part number consists of various codes, including the type of nut, material code, thread size code, shank code, and finish. These codes provide valuable details such as the type of material the nut is suitable for, the thread size, shank size, and finishing options. Understanding part numbers helps users quickly identify the right nut for their project.

Why does shank size matter in self-clinching nuts?

Shank size is crucial in self-clinching nuts as it determines the nut’s ability to grip the material and function effectively. If the shank is too thick for the material, it might protrude when pressed, affecting the aesthetics and function. On the other hand, if the shank is too thin for thick material, the nut won’t grip the material securely. Choosing the correct shank size is essential for ensuring a reliable and secure fastening in precision fabrication projects.

How can I use shank codes to choose the right self-clinching PEM® nuts?

To use shank codes effectively, follow these steps:

1. Identify your desired nut style based on material and thickness.
2. Choose the corresponding thread code.
3. Find the minimum sheet thickness for your material.
4. Determine the shank code that matches your hardware type, thread code, and sheet thickness.
5. Use the part number formula (Type-Material Code-Thread Code-Shank Code-Finish) to locate the appropriate nut.

By following this process, you can confidently select the correct self-clinching PEM® nuts for your precision fabrication projects. If you need expert assistance, don’t hesitate to consult with the Approved Sheet Metal team.