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M22 Thread Dimensions & Specifications

M22 Thread Quick Specifications

Schematic of basic thread dimensions for LCA threaded feed‑through EMI filter, illustrates major diameter, pitch, pitch diameter, minor diameter, thread height and 60° thread profile

ParameterSpecification
Thread StandardISO Metric Threads
Major Diameter22 mm0.8661 in
Pitch2.50.0984 in
Pitch Diameter20.376 mm0.8022 in
Minor Diameter19.294 mm0.7596 in
Thread Height1.353 mm0.0533 in
Addendum0.812 mm0.032 in
Thread Angle60°

Introduction

The M22 thread is one of the most widely used ISO metric screw threads for precision fastening in electronics, automation, instrumentation, medical devices, robotics, telecommunications, and industrial equipment. Defined by the ISO metric thread system, it provides excellent interchangeability and global compatibility across components manufactured to international standards.

This engineering guide provides comprehensive technical information for the M22 metric thread, including thread designation, major diameter, pitch diameter, minor diameter, tolerance classes.

Whether you are designing a new product, selecting fasteners, machining threaded holes, or specifying mounting interfaces for EMI filters and feedthrough capacitors, this page serves as a practical engineering reference.

Quick Answer: The M22 thread is one of the most widely used ISO metric screw threads for precision fastening in electronics, automation, instrumentation, medical devices, robotics, telecommunications, and industrial equipment.

M22 is an ISO metric thread designation where:

  • Mindicates an ISO metric screw thread.
  • 22indicates a nominal major diameter of 22 mm.

Unless otherwise specified, M22 normally refers to the coarse pitch version with a 2.5 pitch.

Understanding the M22 Thread Designation

Unlike Unified threads such as 4-40 UNC or 6-32 UNC, metric thread designations are much simpler.

When pitch is omitted, the designation automatically refers to the standard coarse pitch.

Therefore:

  • M22= M22 × 5

If a fine pitch is used, it must be specified explicitly.

For example:

  • M22× 5 (Coarse)
  • M22× 1 (Fine)

M22 Thread Tolerance Classes

Thread tolerance defines the allowable variation in thread dimensions and determines how tightly an external thread fits with its mating internal thread. Selecting the appropriate tolerance class ensures smooth assembly, adequate preload, and reliable long-term performance.

For ISO metric threads, tolerance classes are specified in accordance with ISO 965-1 and ISO 965-2.

A complete tolerance designation consists of:

  • Tolerance Grade(numerical value)
  • Tolerance Position(letter)

For example:

M22 × 2.5 – 6g

where:

  • 6 = Tolerance grade
  • g = Tolerance position for external threads

Likewise:

M22 × 2.5 – 6H

is the standard designation for an internal thread.

Common Tolerance Classes

Thread TypeCommon ClassTypical Application
External Thread6gGeneral-purpose screws and bolts
Internal Thread6HGeneral-purpose tapped holes and nuts
External Thread4g6gPrecision mechanical assemblies
External Thread8gLoose fit or coated fasteners
Internal Thread7HIncreased assembly clearance

M22 Coarse Thread vs M22 Fine Thread

Many engineers are unaware that M22 is available in more than one pitch.

The two most common versions are:

ThreadPitchStandard Use
M22 × 2.52.5Standard coarse thread
M22 × 11 mmFine thread

M22 × 2.5 (Coarse)

Advantages:

  • Easier assembly
  • Better resistance to cross-threading
  • Faster installation
  • More tolerant of contamination
  • Preferred for general-purpose fastening

Typical applications:

  • Consumer electronics
  • Industrial equipment
  • Enclosures
  • Control panels

M22 × 1 (Fine)

Advantages:

  • More precise axial adjustment
  • Greater number of engaged threads within the same length
  • Better resistance to self-loosening under certain conditions

Typical applications:

  • Optical instruments
  • Precision measuring devices
  • Fine adjustment mechanisms

Frequently Asked Questions (FAQ)

Q1. Is M22 the same as 7/8 – 9 UNC?

No. Although M22 and 7/8 – 9 UNC have similar physical sizes, they are different thread systems.

Q2. What tolerance class is normally used for M22 threads?

The most common general-purpose tolerance pairing is:

External thread: M22 × 2.5 – 6g

Internal thread: M22 × 2.5 – 6H

This combination provides a good balance between:

  • Manufacturing cost
  • Interchangeability
  • Assembly reliability

Q3. What is the difference between M22 × 2.5 and M22 × 1?

The difference is thread pitch.

Q4. Can LCA provide EMI filters with M22 threads?

Yes. LCA supports customized mechanical designs involving metric and inch thread configurations.

Customization options include:

  • Thread size
  • Housing dimensions
  • Electrical parameters
  • Sealing structure
  • Plating options

Engineering Support CTA: Selecting a threaded EMI filter or feedthrough capacitor? Share the thread standard and size, panel thickness, voltage/current, capacitance, and environmental requirements with LCA engineers. View Thread Mount Feedthrough Filters

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