How are standoff screws measured? Standoffs & Spacers explained

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How are standoff screws measured? Standoffs & Spacers explained

What are Standoffs and Spacers? The measurements of Standoff screws.

Standoffs are hex or round-shaped fasteners consisting of a body and two threaded ends. The threaded ends are of two types: threaded opening (female) or an externally threaded post (male). They are commonly used to mechanically support and electrically connect and position components within assemblies and other purposes.

Spacers are similar to standoffs. However, standoffs are threaded on both ends, and Spacers are unthreaded with a hole inside.

What is the definition of Standoffs and Spacers?

According to dictionaries, a Standoff is defined as “a stalemate or a deadlock between two equally matched threads(male and female).” In manufacturing and assemblies, standoffs, and spacer, which we will discuss today, have different meanings.

Who uses Standoffs and Spacers?

If you look inside an assembled circuit board, you will see standoffs and spacers because, in the world of electronic hardware, they are the standard for connecting and mounting circuit boards, computer motherboards.

Both are commonly used to properly position parts within an assembly, reduce component contact, elevate stacked sections, ensure enough room for heat to flow out, and separate or create space between two objects, avoiding any damage to electrical components.

Common types of standoffs for computers

  • Proprietary Standoffs

This type of standoff usually comes with high-end PC frames, usually made from metal. WIth a few PC frames, you may find plastic standoffs with pointed tips and screwable bottoms to secure the motherboard with a base plate. The standoffs are usually shipped with a PC frame, not with the motherboard. So, if you lose these proprietary standoffs, the replacement process is complicated. 

  • ATX factor Standoffs

Most of the motherboards for building a PC are ATX, but the form  factors can vary according to the size and model of the motherboard. For example, Mini and Micro are much smaller than standard size ATX motherboards and contain fewer mounting holes.

With larger motherboards, it is recommended to use metal standoffs near the rear edge and the center while plastic standoffs at the front and its closest edge.

The fact that Mini and Micro standoffs are smaller in size, they usually require no plastic standoffs. Still, the installation and placement of all ATX motherboards are almost the same.

  • Special Standoffs

Unless you are building a legacy or unique computer, you are likely to use an ATX motherboard. But suppose you’re building a tiny box for installation on a very tight space based on FlexATX. In that case, Mini LPX, NLX form factor, the standoff placement might vary like the layout of AT motherboards, which is very hard to find nowadays.

How are standoff screws measured? 

The standoff or screws are often named like  M3*5 screws and come with a flat head, just like any other screw. The name M3 stands for the diameter, which is 3 millimeters, and the five stands for the length, which is 5 millimeters.

You can find standard M3*5 screws online or at any hardware store, so even if you don’t have any right now, you don’t need to worry.

The Best Standoffs

The most popular standoff screw that has been used by thousands of people and has given its stamp of approval

The M3 is yet the best among all standoff screws. The quality and its widespread use make the M3 the best screw in motherboard standoffs. Some of the best features of this standoff screw are :

  • The high-quality brass and steel have superior rust resistance and excellent oxidation resistance, ensuring long-time use.
  • The M3 screw can also be used in installing an internal CPU disk, motherboard, radiator, cooling fan, power supply, graphic card, hard drive, case, monitor, a flat panel screen, or CD-ROM.
  •  M3*6 Tool-Less adjustment makes it easy for everyone to use without requiring any specific tool.

What do I need to consider when selecting standoffs?

Standoffs have a variety of styles based on four main aspects:

1) Shape 

2) Outer diameter of the body

3) Body length 

4) Size of thread

Standoffs and Spacers can be flat, hex, round, or square-shaped. The most common diameter of the body is ¼, but many other sizes are available for multiple uses. Standard body lengths range from ¼ x 2″. Clearance holes and thread generally range from 2 through ¼. Extraordinary lengths and sizes are available almost everywhere. You just need to research your required size.

Standoffs come in three main combinations :

1) Female to Female: They can be fully or partially threaded on each end.

2) Male to Female: Have internal male threads on one end and female threads on the other. Threads are generally the same size.

3) Male to Male: Have external threads on both ends, which may differ in thread size.

What Materials are available?

Common materials include brass, aluminum, plastic/nylon, steel, and stainless steel. Common platings include clear anodized, zinc, gold, and nickel plated. There are generally over 20 standard plating’s available! Some of the most common materials:

Aluminum is popular because of its ratio of strength to weight. It is light, non-magnetic, performs well in severe temperatures, and has nonconductive properties, which helps in preventing any damage to the attached electrical components.

Brass is used in making high-quality standoffs. It is conductive, resists corrosion, and is non-magnetic. It is more costly and heavier than aluminum and is mostly zinc plated or nickel. It can be soldered for grounding.

18-8 Stainless Steel is strong, conductive, and non-magnetic. Stainless steel offers better corrosion resistance than both of these materials.

Steel is used for its strength, but it is heavier than aluminum. It does not resist corrosion like Stainless steel, aluminum, or brass. It is often zinc plated for added corrosion resistance.

Nylon 6/6 is superlight, nonconductive, and resistant to chemicals and solvents. Nylon absorbs moisture, which can affect dimensions and other properties despite its more favorable and safe properties. It is less used than the above mentioned materials.

Most common material

The material used to make these screws is mostly steel, the most common material used. Frequently with a plated or anodized finish. Other materials, including brass, aluminum, nylon, and various plastics, are also used for applications with particular physical or aesthetic requirements.

Material guide chart

Materials Corrosion Resistance Magnetic Conductivity Strength to Weight Color Plates
Steel Low Strongly Yes – Poor Average Grey Available
Aluminum Average No Yes – Average Very Above Average Grey Available
Brass High No Yes – Below Average Average Yellow Available
Nylon High No No Average White-

can be dyed 

No

 

Standoff screw size chart

Inch Standoffs Standard Lengths Available
1/8″ Standoffs 1/8″ – 1″
3/16″ Standoffs 1/8″ – 2″
1/4″ Standoffs 1/8″ – 10″
5/16″ Standoffs 1/8″ – 10″
5/8″ Standoffs 1/8″ – 10″
3/8″ Standoffs 1/8″ – 10″
1/2″ Standoffs 1/8″ – 10″

 

Metric Standoffs Standard Lengths Available
13mm Standoffs 3mm – 51mm
4.5mm Standoffs 3mm – 51mm
6mm Standoffs 3mm – 51mm
8mm Standoffs 3mm – 51mm
10mm Standoffs 3mm – 51mm

 

Precaution when using standoff for motherboards :

  1. You should use standoffs and screws in the locations where you want to prevent the motherboard from bending and might crack it.
  2.  You should always have a screw by the corner near the IO shield. When you insert connectors in the IO shield, the motherboard should be firm to prevent any other damage. It is a good idea to screw in the middle, close to the PCI-e connector, with the proper standoff screwed under the board so that when you insert a video card, the board won’t bend in the middle.
  3.  You should screw the 24pin power connector initially. When you insert that connector into the motherboard, it takes a bit of downwards pressure. If there’s no standoff under the board near that connector, the board would bend and cause severe damage.
  4.  The rest are usually less critical, for example, the bottom corners, because you typically don’t fill all the board with cards to put weight on the motherboard. There’s only a front panel header and SATA connectors on the other corner, so again not much downwards pressure to cause bending.

Summary

Standoffs and Spacers sometimes show up under their Millimeters-spec numbers, which can be crossed to commercial equivalents. Some common Mil-spec series include NAS42, NAS43, NAS61, NAS1056, NAS1057, NAS1829, NAS1830, NAS1831.

How are standoff screws measured?

First of all, you need to measure the outer diameter of the body, the vertical length of the body, and the size of the thread. After that, determine the combination used for the standoff, whether it is a female to female, male to female, or male to male.

All-metric standoffs are stated as threading x hex length x thread length. For example, M3 x 10 x 6. This will be read as M3 male and female threading, 10 mm hex length, and 6 mm threaded length.

A typical Standoff measure is 1/4 hex * 1/2 long * 8-32 thread male-female aluminum standoff. This exact standoff is made and branded by at least 10 manufacturers. Standoffs are mostly referred to by their brand names and are often substituted by generic equivalents. Popular brands include Amatom, Concord, Globe, H.H. Smith, Lyn-Tron, Microplastics, Keystone, Pem, RAF, Unicorp.