Metric Coarse Thread Pitch Chart

What is a Metric Coarse Thread?

Metric Coarse threads are part of the ISO Metric Thread Standard, defined by ISO 261 and ISO 965. They feature a distinctive 60° thread profile and represent the default, most commonly used metric thread standard worldwide. Metric Coarse is the go-to choice for the vast majority of industrial applications.

Compared to Metric Fine threads, Metric Coarse threads have a larger pitch, which offers several practical advantages. The larger pitch makes assembly quicker, provides greater resistance to thread damage during installation, and makes them better suited for general-purpose applications where reliability and ease of use are priorities. You'll find Metric Coarse threads widely used across manufacturing, automotive, construction, machinery, maintenance and industrial engineering sectors.

How to Read the Metric Coarse Thread Chart

The chart above displays the key dimensions for each Metric Coarse thread size. Here's what each column represents:

• Diameter – The nominal thread size designation (for example, M8, M10, M12). This is the standard way to identify a metric thread.
• Pitch (mm) – The distance between consecutive thread crests, measured in millimetres. This determines how quickly the thread advances with each rotation.
• Drill Size (mm) – The recommended tap drill size for creating a threaded hole. Using the correct drill size ensures proper thread engagement and strength.

This reference chart covers the full range of ISO Metric Coarse thread sizes from M1 through M60, making it an essential engineering thread chart for any workshop or manufacturing environment.

Common Applications

Metric Coarse threads are the backbone of modern industrial fastening. You'll encounter them in general engineering projects, manufacturing facilities, industrial machinery assembly and maintenance, construction work, automotive manufacturing and repair, agricultural equipment, and fabrication workshops. Their reliability and ease of use make them the preferred choice across virtually every sector that relies on threaded fasteners.

Frequently Asked Questions

What is a Metric Coarse thread?
A Metric Coarse thread is a standardised thread profile defined by ISO 261 and ISO 965, featuring a 60° angle and a larger pitch than Metric Fine threads. It's the most widely used metric thread standard globally.

What is the difference between Metric Coarse and Metric Fine?
The primary difference is pitch. Metric Coarse threads have a larger pitch, making them faster to assemble and more forgiving of minor damage. Metric Fine threads have a smaller pitch, offering greater thread engagement and load capacity in applications where space is limited.

Why is Metric Coarse the standard thread?
Metric Coarse is the default standard because it balances ease of assembly, strength, and versatility. Its larger pitch makes it quicker to install and more resistant to cross-threading, making it ideal for general-purpose applications across industries.

Are Metric Coarse threads interchangeable with imperial threads?
No. Metric Coarse threads and imperial threads (such as UNC or UNF) are not interchangeable. They have different pitch angles, pitch measurements and diameter standards. Always verify the thread type before selecting fasteners or tooling.