Side-by-Side Comparison
Metric Threads (ISO)
M2.5 Thread vs. M4 Thread
Comparing 2 standards across 7 specifications. 7 key differences identified.
Comparing:
M2.5 Thread
M4 Thread
M2.5 is an ISO metric machine screw thread with a nominal major diameter of 2.5 mm and a standard coarse pitch of 0.45 mm. Requiring a 2.05 mm tap drill, it is the standard fastener for 2.5-inch SATA/SAS hard drive caddies, Raspberry Pi mounting standoffs, and consumer drone frames.
M4 is an ISO metric machine screw thread with a nominal major diameter of 4.0 mm and a standard coarse pitch of 0.70 mm. Requiring a 3.30 mm tap drill, it is the mandated standard fastener for VESA MIS-D (75×75 mm and 100×100 mm) computer monitor and small TV wall mounting brackets.
Specification Comparison Table
7 Parameters| Parameter / Spec | ||
|---|---|---|
|
Nominal Major Diameter
|
2.50 mm | 4.00 mm |
|
Standard Coarse Pitch
|
0.45 mm | 0.70 mm |
|
Fine Pitch (Optional)
|
0.35 mm | 0.50 mm |
|
Tap Drill Diameter
|
2.05 mm (75% thread engagement) | 3.30 mm (75% thread engagement) |
|
Minor Diameter (Internal)
|
2.013 mm | 3.242 mm |
|
Tensile Stress Area
|
3.39 mm² | 8.78 mm² |
|
Common Drive Size
|
PH1 / T8 / 2.0mm Allen | PH2 / PZ2 / 3.0mm Allen / T20 |