Side-by-Side Comparison
Metric Threads (ISO)
M3 Thread vs. M8 Thread
Comparing 2 standards across 7 specifications. 7 key differences identified.
Comparing:
M3 Thread
M8 Thread
M3 is an ISO metric machine screw thread with a nominal major diameter of 3.0 mm and a standard coarse pitch of 0.50 mm. Requiring a 2.50 mm tap drill, it is the world's most widely deployed fastener in 3D printers, consumer electronics, and PC 5.25-inch optical drive bays.
M8 is an ISO metric machine screw thread with a nominal major diameter of 8.0 mm and a standard coarse pitch of 1.25 mm. Requiring a 6.80 mm tap drill, it is the standard fastener for VESA MIS-F large TV wall mounts (400×400 mm and 600×400 mm), automotive suspension brackets, and heavy furniture.
Specification Comparison Table
7 Parameters| Parameter / Spec | ||
|---|---|---|
|
Nominal Major Diameter
|
3.00 mm | 8.00 mm |
|
Standard Coarse Pitch
|
0.50 mm | 1.25 mm |
|
Fine Pitch (Optional)
|
0.35 mm | 1.00 / 0.75 mm |
|
Tap Drill Diameter
|
2.50 mm (75% thread engagement) | 6.80 mm (75% thread engagement) |
|
Minor Diameter (Internal)
|
2.459 mm | 6.647 mm |
|
Tensile Stress Area
|
5.03 mm² | 36.6 mm² |
|
Common Drive Size
|
PH1 / PH2 / 2.5mm Allen / T10 | 13mm Hex / 6.0mm Allen / T40 / T45 |