Diamond blade compatibility: bore, arbor, flanges and RPM
A diamond blade fits only when its approved mounting arrangement and speed rating match the saw, as well as its diameter and intended use. A centre hole that appears to fit the shaft is not enough. Confirm the bore, flanges, any drive-pin arrangement and the machine's specified blade-shaft speed before ordering or installing it.
What the mounting terms mean
| Term | What to identify |
|---|---|
| Bore or arbor hole | The blade's centre opening, including its exact specified size and form |
| Arbor or spindle | The machine-side mounting shaft/interface; check how the manual names and dimensions it |
| Flanges or collars | The approved components that locate and clamp the blade |
| Drive or locking pin | A locating/drive feature used by some mounting systems; its matching hole arrangement matters |
| Blade-shaft RPM | Rotational speed of the shaft carrying the blade, not simply the engine speed |
| Maximum blade RPM | The blade manufacturer's maximum permitted rotational speed |
Terminology varies between manuals and suppliers. Send the relevant manual page or drawing as well as the dimension; “standard bore” does not identify a complete interface.
Check the whole mounting arrangement
Obtain the blade requirements for your exact saw and variant. Compare the supplied blade specification with the permitted diameter, bore and flange arrangement. Where the saw uses a pin, confirm the required hole configuration too.
For example, the Husqvarna FS 400 LV manual, pages 12–13, shows an inner flange, outer flange and locking pin; the pin must pass through the blade into the outer flange. That arrangement illustrates why bore size alone cannot establish fit. It is not a universal installation pattern.
Before fitting a blade, isolate the machine as its manual directs and let hot parts cool. Follow the model's installation procedure, including contact-surface checks, rotation direction and specified fastening requirements. Worn, damaged or dirty mounting parts need attention before installation.
Do not drill or file a blade hole, force a blade onto a shaft, or improvise with loose washers or sleeves. If a reducing bush or other mounting component is proposed, obtain explicit manufacturer approval for that complete blade-and-machine arrangement. Its presence in a package does not establish compatibility with every saw.
Compare the right speed figures
Use the machine's specified blade-shaft speed for the actual configuration. Engine RPM and blade-shaft RPM are different quantities; a belt or transmission arrangement can make them different values.
The blade's maximum permitted RPM must be at least as high as the machine's specified blade-shaft speed for that setup. The FS 400 LV manual, page 11, explicitly requires a blade rated for the same speed or higher than the product type-plate value. Consult your own manual for the applicable speed reference.
Passing this check does not establish the best cutting speed. A maximum RPM marking is a limit, not a productivity target. Follow the machine's operating instructions and blade manufacturer's recommended operating conditions. Where speed settings or approved blade configurations can change, check the applicable setting rather than borrowing a value from another diameter or saw.
If a label is missing, illegible or inconsistent with the documentation, resolve the rating with the manufacturer before use. Do not guess from the product's nominal inch size.
Send a compatibility enquiry that can be answered
Include the machine make, model and variant; the relevant manual pages; the proposed blade link and specification; the blade-shaft speed; bore and flange details; and any pin arrangement. Add clear photographs of readable labels and, only with the machine safely isolated, accessible mounting components. Photographs support identification but do not replace dimensions or ratings.
Use the diameter and cutting-depth guide for capacity checks. To discuss a Jagson listing, send the compatibility details before ordering. Request confirmation for the exact blade specification rather than for a whole machine brand.