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

M1.6 Thread vs. M5 Thread

Comparing 2 standards across 8 specifications. 8 key differences identified.

Comparing:
M1.6 Thread
M5 Thread

M1.6 is a miniature ISO metric machine screw thread with a nominal major diameter of 1.6 mm and a standard coarse pitch of 0.35 mm. Requiring a 1.25 mm tap drill, it is the standard fastening thread for precision optical equipment, wristwatches, and micro-electronic assemblies.

View full M1.6 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

8 Parameters
Parameter / Spec
Nominal Major Diameter
1.60 mm 5.00 mm
Standard Coarse Pitch
0.35 mm 0.80 mm
Fine Pitch (Optional)
0.20 mm 0.50 mm
Tap Drill Diameter
1.25 mm (75% thread engagement) 4.20 mm (75% thread engagement)
Minor Diameter (Internal)
1.221 mm 4.134 mm
Tensile Stress Area
1.27 mm² 14.2 mm²
Thread Profile Angle
60 degrees
Common Drive Size
4.0mm Allen / T25 / PH2