M2x0.25 Thread Specs

Standard: ISO 261 (ISO Metric Fine)

ISO Metric Fine
This reference guide outlines the technical dimensions and tapping parameters for the standard M2x0.25 metric thread. Part of the ISO Metric Fine series defined by ISO 261, the thread features a nominal diameter of 2 mm and a pitch of 0.25 mm. For machining or fabrication, the recommended tap drill size is 1.75 mm (for 75% thread depth) or 1.77 mm (for 65% thread depth).

Dimensional Specifications (mm)

Nominal Diameter 2 mm
Pitch 0.25 mm
Threads per mm 4
Major Diameter 2 mm
Pitch Diameter (d₂) 1.838 mm
Minor Diameter (d₁) Ext 1.729 mm
Minor Diameter (D₁) Int 1.765 mm
Thread Height 0.217 mm
Root Radius 0.036 mm

Drilling & Strength Specs

Tap Drill (75%) 1.75 mm
Tap Drill (65%) 1.77 mm
Stress Area 2.45 mm²
Stress Diameter 1.693 mm
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Frequently Asked Questions

What is the tap drill size for a M2x0.25 thread?

For standard thread engagement (approx. 75%), the recommended tap drill size for M2x0.25 is 1.75 mm. For a slightly looser 65% thread engagement, a 1.77 mm drill bit is recommended.

What is the pitch of a M2x0.25 thread?

The thread pitch for a standard M2x0.25 thread is 0.25 mm, which equates to approximately 4 threads per millimeter.

What are the major and pitch diameters for M2x0.25?

The nominal major diameter of M2x0.25 is 2 mm. The calculated pitch diameter (d₂) is 1.838 mm per the ISO 68-1/ISO 261 standards.

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