M10 Bolt Size and Thread Specifications
Quick answer
M10 bolts use 10mm major diameter with 1.5mm coarse pitch and an 8.5mm tap drill.
They handle medium structural loads and common automotive hardware.
Use the chart below and screw size conversion when you align metric with inch bins.
Bolt sizing and thread specifications follow widely recognized mechanical standards used in engineering and manufacturing. Standard bolt sizing references, industrial fastener charts, and mechanical thread standards ensure compatibility, safety, and correct tool selection across applications.
M10 is a common metric bolt size for automotive, machinery, and structural applications. A 10 mm nominal diameter with 1.5 mm pitch offers strong clamp load and is standard in many industries. Spanish reference: perno M10. For tap drill size, thread types, and thread identifier workflows, pair this page with tools as you verify threads.
Specifications
| Specification | Value |
|---|---|
| Nominal diameter | 10 mm |
| Standard pitch | 1.5 mm |
| Fine pitch | 1.25 mm |
| Tap drill size | 8.5 mm |
| Closest imperial equivalent | 3/8-16 |
Hex head size
| Bolt size | Hex head size |
|---|---|
| M10 | 17 mm |
Common uses
M10 bolts are used in automotive engines and chassis, machinery, structural steel connections, and heavy-duty hardware. They are a standard choice for high-clamp applications. Cross-check loads with the bolt size chart and screw size conversion when you mix metric and inch bins.
Related tools
Related charts
M10 vs M12 bolt size
Shank diameter and pitch set tap drill, hex key, and strength for each ISO size. Compare values in the tables above with the M12 bolt size page when you resize hardware.
Use the bolt size chart when you compare hex and shank columns across sizes.
Metric vs UNC thread size
Metric threads list diameter in millimeters and pitch in millimeters per thread; UNC lists nominal inch diameter and threads per inch. They are not interchangeable—taps, dies, and gauges differ.
Read metric vs unc thread context when series labels are unclear.
Use screw size conversion when you must match stocked parts.
M10 specifications and tools
How to choose the right bolt size
Choosing the correct bolt size depends on load, material, and thread type. Larger diameters increase strength, while thread pitch affects holding force.
Use the bolt size chart to compare shank and hex dimensions before you standardize hardware.
Use tap drill size guidance when you plan tapped holes.
Use the thread identifier when stamped sizes are missing.
FAQ
What is the standard pitch for an M10 bolt?
The standard pitch for M10 is 1.5 mm. Fine pitch is 1.25 mm.
What drill size should be used for tapping M10 threads?
For M10 x 1.5 coarse thread, use an 8.5 mm tap drill. Use our Tap Drill Calculator for other pitches.
What imperial bolt is closest to M10?
3/8-16 UNC is the closest imperial equivalent to M10.