M17 Bolt Size and Thread Specifications
Quick answer
M17 bolts use 17mm major diameter with 1.5mm coarse pitch in reference tables.
They are specialty sizes between M16 and M18 in some OEM lines.
Use the tables below and the bolt size chart when you compare adjacent diameters.
M17 is uncommon compared with M16 or M18. Replacement usually requires matching the exact thread pitch and strength class from the equipment manual. Spanish reference: perno M17. For tap drill size, thread types, and thread identifier workflows, pair this page with tools as you verify threads.
Specifications
| Specification | Value |
|---|---|
| Nominal diameter | 17 mm |
| Standard pitch (coarse) | 1.5 mm |
| Tap drill size | 15.5 mm |
| Closest imperial equivalent | 5/8-11 (approx.) |
Hex head size
| Bolt size | Hex head size |
|---|---|
| M17 | 27 mm |
Common uses
Specialized equipment and spares that call out M17 explicitly. Cross-check loads with the bolt size chart and screw size conversion when you mix metric and inch bins.
Related tools
Related charts
M17 vs M18 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 M18 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.
M17 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 M17 bolt?
The common coarse pitch for M17 is 1.5 mm. See drawings for fine or special pitches.
What drill size should be used for tapping M17 threads?
For M17 x 1.5 coarse thread, use approximately a 15.5 mm tap drill. Use our Tap Drill Calculator for other pitches.
What imperial fastener is closest to M17?
5/8-11 (approx.) is a practical reference for comparing M17 to inch hardware; verify fit for your application.