Axle thread pitch
Thread pitch is the distance between the threads of the thru-axle, and there's no single standard: the same 12 mm diameter can use M12×1.0 (SRAM/Specialized), M12×1.5 (Shimano E-Thru) or M12×1.75 (RockShox Maxle), depending on the frame or fork brand. It's the most overlooked and most dangerous figure: if you force an axle with the wrong pitch, you destroy the frame thread irreversibly. That's why width and diameter aren't enough: you also need the right pitch.
It's the silent trap of the thru-axle: two axles identical on the outside can have incompatible threads that ruin your frame.
What it is and why it matters so much
The pitch (1.0, 1.5 or 1.75 mm) defines how far the thread advances per turn. An M12×1.0 axle won't enter an M12×1.75 frame even though both are «12 mm»: the thread doesn't match. Forcing it strips the frame insert threads, an expensive and sometimes unrepairable damage. So when replacing a thru-axle, respect the brand/pitch or measure it.
The three common pitches
What it fits
The axle must match in diameter (M12) and pitch (1.0, 1.5 or 1.75) with the frame or fork insert. UDH frames use M12×1.0 with 12.7 mm of thread. If unsure, don't force it: identify the pitch before threading.
If you don't know which axle, width or thread your frame uses, send us the case. Real diagnosis, nothing to sell you. Message us on WhatsApp
Frequently asked questions
How do I identify my axle's thread pitch?
With a thread gauge, or by measuring 10 consecutive threads: 10 mm means 1.0; 15 mm, 1.5; 17.5 mm, 1.75. When in doubt, take the axle to the shop.
Why is there no single standard?
Each brand (SRAM, Shimano, RockShox) adopted its own pitch. That's why axles of equal diameter and width can be incompatible.
What pitch does a UDH frame use?
M12×1.0, with a thread length of 12.7 mm, per SRAM's specification.