# item.guide
Side-by-Side Comparison Metric Threads (ISO)

M2.5 Thread vs. M5 Thread

Comparing 2 standards across 7 specifications. 7 key differences identified.

Comparing:
M2.5 Thread
M5 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.

View full M2.5 Thread spec sheet →

M5 is an ISO metric machine screw thread with a nominal major diameter of 5.0 mm and a standard coarse pitch of 0.80 mm. Requiring a 4.20 mm tap drill, it is the universal standard for bicycle water bottle cages, disc brake rotor mounts, and 2020/4040 aluminum extrusion T-slot framing nuts.

View full M5 Thread spec sheet →

Specification Comparison Table

7 Parameters
Parameter / Spec
Nominal Major Diameter
2.50 mm 5.00 mm
Standard Coarse Pitch
0.45 mm 0.80 mm
Fine Pitch (Optional)
0.35 mm 0.50 mm
Tap Drill Diameter
2.05 mm (75% thread engagement) 4.20 mm (75% thread engagement)
Minor Diameter (Internal)
2.013 mm 4.134 mm
Tensile Stress Area
3.39 mm² 14.2 mm²
Common Drive Size
PH1 / T8 / 2.0mm Allen 4.0mm Allen / T25 / PH2