High Speed Steel can be effectively used in certain applications, and while it’s often the product of choice for some metalworkers and larger industrial organizations, bi-metal can actually be more potent and effective when used for certain metals and sizes. These are two completely different styles of cutting, and in order to fully appreciate the bi-metal blades, it’s good to understand what HSS offers.
HSS, or High Speed Steel
When cutting thin sheet steel and fiberglass, there’s going to be a significant amount of flexibility. While this flexibility is not going to be visible to the naked eye, it still exists. If a blade were to cut through these thinner materials, it would cause the metal to be forced one way, then the next. That’s not conducive to a smooth cut.
In many situations, achieving a straight cut is important, but it also needs to be smooth, ergo the focus on high speed metal for these surfaces. With a high speed steel, it’s usually a semi-circular or full round flat blade. It offers more uniformity and a much smoother cut for the thinner materials that need to be worked.
Bi-Metal
A bi-metal blade is constructed using a high speed steel ribbon and spring steel. They are welded together using electron-beam welding and this leads to much stronger durability. This makes the bi-metal blade much more potent for medium to thick steel surfaces.
It comes down to the basics of what the blades are used for.
Experienced metalworkers understand there are numerous types of situations and circumstances in which a wide range of materials, including machines and the blades used with them, will be required. Not everything can be simplified down to the point of stating: use ‘this’ blade or type of cutting surface and it’s better than all others for any application.
A bi-metal blade is not going to be the ideal option for thin sheet metal or fiberglass, as we already noted. If used in this situation, there may be a number of problems, including an uneven cut, sharp, jagged edges, shredding of materials and so on.
Using HSS blades to cut through thick metal means there will likely need to be many more blades used to complete the same job that one bi-metal blade could perform.
So, the question for some may boil down to which is ideal when getting into medium thickness metals? If the HSS blades are better for thin sheet metal surfaces, and the bi-metal is ideal for thicker metals, then what about middle of the road thickness?
This could be a problem for some companies.
Either one may work out in the end. The HSS will certainly provide a smoother cut than the bi-metal blades for these thicker materials, but it’s going to cost. The number of blades used to complete each assignment is going to depend on a number of factors, but it could be half a dozen, two dozen, or more to one bi-metal blade.
Is the finished cut important?
How important is it to have a smooth cut? This is a crucial question to be asking when faced with these concerns. While grinding wheels are effective at smoothing surfaces, it’s not always practical. It will require more man hours to complete the task when a grinding wheel has to be taken to the surface to smooth it out when using a bi-metal blade.
Some project managers and supervisors may see a benefit in reducing the number of man hours needed for grinding down a rough finish compared to saving blades. However, when taken as a whole, it’s necessary to realize that changing these HHS blades also requires down time, man hours, and safety procedures to be followed that are likely already in place.
On the other side of the argument, one would have to admit that yes, using a grinding wheel or other tool to smooth out the surface may be necessary when using bi-metal blades, but the likelihood of that being absolutely necessary are often slim, even remote. That’s because, when used in proper applications (such as when cutting through medium thickness sheet steel), there will be other work required on that cut piece of metal. It may need to be welded, bend, or worked in another manner to achieve the desired finished goal.
The Bottom Line
At the end of the day, money talks. As a result, when one balances the needs for prospective smoothing out of the metal surfaces with the inherent costs and durability of these blades, there’s really no comparison.
As noted earlier, for thin sheet steel, HSS (high speed steel) blades are the better option, without question.
But (and this is a big but), when the steel that needs to be cut is medium to thick, then there’s nothing better than bi-metal. It lasts longer, is built with a more durable material, and will provide a decent cut edge, though not nearly as smooth as one could achieve with the HSS blades.
Any Other Advantages to Bi-Metal Blades?
There is one other important advantage to relying on bi-metal blades and that has to do with flexibility. HSS and other carbon body blades are rigid, which means they will not bend or flex at all. They are designed to cut and in order to do that to peak efficiency, they simply cannot give.
This means if there is some need for flexibility in cutting, either due to the material, bends needed, and more, then the HSS blades are not going to offer that option. However, the bi-metal blade does.
While it is far more durable and will last a lot longer than the HSS blades we’ve been comparing them to, they are also flexible. This can be extremely important in various applications. When the blade is flexible, it will bend when needed, at least to some degree, and that can mean the difference between breaking (as the high speed steel blades are prone to do) and continuing on with the cut.
The bottom line is simple: for most applications, bi-metal is the best option.