Choosing the right diamond saw blade can be really confusing with a multitude of blade arbor sizes, diameter and thickness options. Prices vary widely and blade quality can vary just as much. We recommend that once you find a blade that suits your needs and budget, it is good to stick with it.
Diamond blades do not really cut - it is actually a grinding action using diamond crystals embedded into the edge of the blade. So dont force the blade to cut the stone but allow the blade to work at its own pace. Power feed attachments are good for this if you are working with large rocks.
Lapidary saw blades can be damaged if used dry so make sure you follow the manufacturers recommendations for coolants. Generally, you should be able to use water alone for the smaller sizes while the larger sizes will need some kind of lubricant such as a light water-based oil.
When purchasing a saw blade, first make sure of your arbor size. Most blades can be supplied with a bush to adjust bore size. 5/8" or 1/2" is a common bore size.
Your saw will determine the diameter required for the blade so you'll already know this information. The next decision is Blade type - generally you will be choosing between a notched or continuous rim blade. Usually notched rim blades will be cheaper but not quite as long-lasting while the continuous rim blades cost a little more and should last longer with proper use.
Blade thickness will depend on what type of material you are working with. We stock diamond blades from 0.012" up to 0.067" in thickness - thicker blades result in more wastage so go as thin as is practical for your work. If you are working with hard, dense material where loss of material is not such as issue (such as agate, jasper, etc), then a thicker blade is recommended. If you are working with precious gems, then you want as little wastage as possible and we recommend a blade no thicker than 0.032" for these jobs.
Thinner blades are more easily damaged so should be used with care. Thin blades would be used at higher rpm's compared to thicker blades. For slabbing, thicker blades are generally recommended - use thin blades only if the slab saw is in good condition and capable of high speeds.