“European” to US screw nomenclature mapping (and reverse)

What is the numbering system for screws?

The first number is the diameter. The bigger the number the bigger the screw. The second number is the number of threads per inch.

How do you read a screw code?

In the Unified Thread Standard (UTS) system, manufacturers list the diameter size as a number between 0 and 10, with 0 being the smallest and 10 being the largest. Screws larger than a #10 have a diameter listed directly in inches. For example, on a #4-40 UNC-3A x . 5 screw, #4 represents the diameter.

What do the #s on screws mean?

A screw for wood is sized by two distinct numbers, first is the gauge of the screw which is the diameter. This means, the larger the number the larger the diameter. Therefore, a number 12 screw is larger than a number 4 screw.

How do you read American screw sizes?

Quote from the video:
Quote from Youtube video: The american screw size formula is equivalent to the screw size number times 13 thousandths of an inch plus sixty thousandths of an inch. That's going to give you the major diameter of the screw.

How do you label a screw?

The number can tell you a lot about the screw so you can find what you need for your intended use.



Some of the information it shows you includes:

1. Length.
2. Shank thickness.
3. Threads per inch.
4. Material thickness the screw’s tip can drive through.

Is a #8 or #10 screw bigger?

Machine screws are often found in sizes of: 0, 1, 2, 3, 4, 5, 6, 8, 10, 12, 14—the larger the number, the larger the screw.

How do you read a metric screw callout?

Metric threads express diameter with M followed by the diameter in millimeters, like example C. Understand the second number in the callout – This indicates the distance between threads. It can be expressed as the number of threads per unit or as the distance between identical threads (the pitch).

What does M10x1 5 mean?

Understanding Inch & Metric Thread Callouts



For example, an M10x1. 5 (coarse) thread has a 1.5mm pitch, while an M10x1. 25 (fine) thread has a 1.25mm pitch. To simplify metric thread callouts, the international (ISO) standard for metric threads eliminates the pitch callout on coarse threads.

How do you read screw sizes UK?

To measure the diameter of screws and bolts, you measure the distance from the outer thread on one side to the outer thread on the other side. This is called the major diameter and will usually be the proper size of the bolt.

What diameter is a 14g screw?

6.30mm

14g (6.30mm) Stainless A2-70 G304 Countersunk Phillips (PH3) Coarse Wood Screws JIS B1112.

What does m8x1 25 mean?

For metric fasteners, you will see a M8 x 1.25 or an M8 x 1. For thread pitch, the distance between two points is the second number meaning the higher the number the fewer threads there are. This means the M8 x 1.25 is the coarse threading and the M8 x 1 is the fine thread.

What is a #4 screw size?

A 4 gauge screw will have a head that is approximately 4mm wide. This is actually quite complicated, as was pointed out by Paul, one of our readers! Here is a more concise explanation of the relationship between gauge (imperial), diameter (metric in mm) and Head size.

What does M5 mean in screws?

Coarse and Fine pitch for the sizes you asked about: M3-0.50 and M3-0.35. M4-0.7 and M4-0.5. M5-0.8 and M5-0.5.

Does M10 mean 10mm?

If the size is M10 x 25, that would mean that the diameter is 10 mm.

Are M6 and 1/4 the same?

A normal M6 screw is a rattly fit in a 1/4 BSF full nut.

Are M5 and 10 32 interchangeable?

10/32 is slightly smaller in diameter than M5. You can use a 10/32 screw in an M5 nut pretty safely. The inverse is not true.

What is M in screw sizes?

The letter ‘M’ indicates that this bolt uses a metric thread. The number ‘8’ refers to the nominal diameter of the bolt shaft in millimeters. The number 1.0 is the thread pitch of the bolt, which is the distance between threads, in millimeters.

What is the metric equivalent to 10-32 screw?

Fastener Conversion Chart