Diablo sent me a whole shipment of various blades to review over the next few months so I’m like a kid in a candy store right now. Today I’m breaking out the carbide recip blades to see how they compare.
Diablo’s carbide blades always make a great first impression. If you’ve ever held one you know what I mean. If you’re used to only using bi-metal blades then you’ll find these carbide blades are a lot more stout than you’re used to. The tooth-count is also quite a bit different with carbide than that of a bi-metal blade because heat build-up is a big issue when cutting hard steel. If you compare the two side-by-side, the bi-metal will have anywhere between 18-24 teeth per inch, whereas a medium metal carbide blade typically has 10 teeth per inch. The teeth on a carbide blade are a lot stronger, so not so many of them are needed to do the same work as a bi-metal blade. This design also allows for more heat dissipation between the teeth, which helps keep heat down.
Heat and vibration are the two big destroyers of blades and bits, so between the rigidity of the carbide blades and the ability for the blade to cut through material quicker means that the blades can last a lot longer than a typical bi-metal blade.
The first blade I tested out was the thin-metal carbide blade. This is a unique blade in that it still has 20 teeth-per-inch like a typical bi-metal blade, however rather than making each tooth carbide and tacking them on to the blade as they would on a medium or thick metal carbide blade – they build an entire carbide strip of teeth and secure that strip to the rest of the blade.
This blade is meant to cut extremely hard metals, that are thin. Be careful not to use it on extremely thin light metal or the heat will build up to a point of damaging the blade. I actually ripped an inch of that strip off of the blade when I used it to cut thin aluminum because of the heat generated, combined with the material vibrating as I was cutting. The blade is designed to cut hard metals like stainless steel, cast iron, and high-strength alloys that are less than 1/8” inch thick. Any use beyond that will destroy the blade or at least degrade it much quicker.
Next up is the medium-metal 10-teeth per inch carbide blade. This blade claims to be able to cut all metals, including strut, pipe, cast iron, and stainless steel. This is what I would consider a general use metal blade, as long as that use is on materials between 1/16-inch and 5/16-inch. If you attempt to cut metals thinner than 1/16” you will damage the material becuase there’s not enough teeth per inch to really cut smoothly. Also cutting anything above and beyond 5/16” will heat the blade up too much making it short-lived and probably tearing a few teeth off along the way.
When used correctly, however, this blade is a beast. It cuts through material precisely, and lasts many cuts. I do recommend taking care of this blade because it is expensive. With all blades and bits, heat and vibration are concerns so it may not be a bad idea to use a cutting medium like oil to help reduce heat build up. Also starting your cuts at a slow and then ramping up is a way to ensure these blades will last you much longer.
The thick-metal carbide blade is also a beast. This thing will cut materials up to 9/16” thick, which is slightly over 1/2” of solid steel. The blade cuts like butter at first but you will find that cutting anything that thick will dull a blade with the quickness, if you don’t back off from time to time to let the heat dissipate. I will say this again, heat and vibration kill blades. If you notice sparking occuring it means that the blade is getting too hot and you need to back off for a minute before continuing to abuse the teeth. But if you’re cutting beams, cast-iron, stainless steel, or hard alloys like other carbides, this blad will more than suffice.
Last up is a typical 20 teeth-per-inch bi-metal blade. These are a lot cheaper blades, as there’s no carbide component to the teeth. For electricians though, the bi-metal blade is probably still the most viable option for cutting strut and thin-wall conduit. The thin metal-carbide is a more beefed-up version of this blade, but it comes at a higher price. Some people prefer to burn through many of these bi-metal blades rather than buying one carbide that could last through the same amount of cuts. I think its 6 of one, and half-a-dozen of the other. I especially recommend using these over the thin-metal carbide when cutting thin sheet-metal or aluminum studs. It can handle the cut quickly and efficiently, and won’t destroy the carbide strip. These blades are still extremely viable options, so don’t feel like just because everyone is going carbide that these bi-metal blades are not still excellent blades. They are. Especially the ones from Diablo.
Make sure that you know exactly what use you’re applying these blades to. I recommend following what is printed on each blade specifically to ensure that they last you a long time. Also keep an eye on heat and vibration. You do all of these things and these blades will treat you right, and I promise you’ll never jump ship for another brand. I’m Diablo all the way.