What you should know about HSS and carbide hole saws
There are hole saws in different variations: HSS, tungsten carbide and bi-metal hole saws. In this article we take a closer look at the properties of HSS and tungsten carbide hole saws.
Above a certain diameter size, drill holes can no longer be drilled with the twist drill, as the amount of material to be cut would be too large and the drilling process would take extremely long.
For these large diameters, e.g. metal pipe entries, hole saws are used.
The great thing about the hole saw is that it is hollow in the middle and only the cutting edges cut the material (and therefore not the complete material).
The diameters of our hole saws, depending on the model, start at 12 mm and go up to 210 mm for bi-metal hole saws. You can find out more about bi-metal hole saws in our article "Bi-metal hole saws and its applications".
Hole saws are always right-cutting, can be used with the hand or stand drilling machine and have a high concentricity.
Note: When drilling with the hole saw, it is important to observe the corresponding speed table. There are different speed tables for tungsten carbide hole saws and HSS and bi-metal hole saws.
Properties of HSS and tungsten carbide hole saws
The HSS and carbide hole saws have cutting edges made of HSS or tungsten carbide (TC).
The main body, however, consists of a different tool steel and the cutting edges are soldered to the main body. The large cutting edges ensure a rather coarse cut quality.
In our program we divide the tungsten carbide into
The differences here lie in the cutting depth and the connected application. This is described in more detail below.
The HSS and tungsten carbide hole saws are equipped with pilot drills and optionally with an ejector spring . Additionally, there are different arbor holders for the corresponding drill chuck.
The pilot drill allows simple centering and clean guidance in the material. With the ejector spring, as the name suggests, the cut material is ejected from the hole saw.
Application of HSS and tungsten carbide hole saws
The HSS and tungsten carbide hole saws are particularly suitable for metal cutting.
When cutting steel or metal, make sure you are using the correct number of revolutions per minute (rpm). In the speed table for HSS and TC hole saws you will find the proper speeds.
Since tool steel HSS (high-speed steel) is softer than tungsten carbide, the areas of application are divided as follows:
| hole saw | Fields of application |
|---|---|
| HSS hole saws | Steel (N/mm2) < 800, aluminium, brass |
| Tungsten carbide hole saw | Steel (N/mm2) < 1,300, stainless steel, aluminium, brass, bronze, cast iron, and Titanium alloyed |
When drilling steels, metals and non-ferrous metals, we highly recommend the use of coolants.
The tungsten carbide hole saws shallow cut have a low cutting depth and are well suited for use with hand drills, as only a lower force is required here. Their cutting depth is limited.
The TC multigrade hole saw MHS has a higher cutting depth, however, from a certain diameter they can only be used with core and column drills.
| Depths of cut | HSS hole saws | TC hole saw, shallow cut | TC multigrade hole saws (MHS) |
|---|---|---|---|
| in steel up to approx. | 2,5 mm | 2,0 mm | 20,0 mm |
| in plastics up to approx. | 5,0 mm | 4,0 mm | 28,0 mm |
| in gypsum, lightweight panels up to approx. | 5,0 mm | 4,0 mm | 28,0 mm |
Summary
HSS and tungsten carbide hole saws are ideally suitable for metal cutting. You can use the shallow cut to cut steel up to 4.0 mm thick. For alloyed and unalloyed steels, the MHS can even cut to depths of up to 20.0 mm. HSS and TC hole saws are also ideally suited for use in aluminium and plastics.
When drilling with the HSS or TC hole saw, you should read our user instructions:
- drill with light, steady pressure
- avoid pendulum movements while drilling
- observe table of drilling speeds
- use prescribed cooling agents
- unsuitable for percussion-drill operation
You can find the three hole saws on the following product pages:
Our complete range of hole saws including accessories such as ejector spring and arbor holders can be found under Products > Hole saws.
If you have trouble finding the right hole saw, please do not hesitate to contact us.