Flap discs are a special type of stone for grinding surfaces of ferrous metal and stainless steel. The accessory is a set of separate fragments. They are flaps with an abrasive stone which is glued to fiberglass canvas with the special compound by baking method. There are two kinds of flap discs depending on the type of work material:
- For ferrous metal. Such discs are created from flaps covered with the specially selected abrasive compound. This compound is based on aluminum oxide which is able to grind steel from A10 to A80.
- For stainless steel from Z40 to Z120 which is made from flaps and soaked with the abrasive mixture based on zirconium.
The peculiarity of such wheels is that they are caliciform and flaps are somewhat angled to the plane of contact. It relieves working process because there is no need to press the tool with the entire plane to work surface. At the same time it provides the maximum area of stone contact with metal.
Flap discs differ in color for relieving the process of recognizing the type of accessories. There is a red sticker on discs for processing metal parts and a blue sticker for stainless steel. However different manufacturers can have their own way of dividing these wheels. In addition to color some of them are also indicated the numbers 40A or 40Z. This points out that the disc can be used to process ferrous metal and stainless steel.
Structurally the wheel is arranged as follows:
the base is made of several fiberglass caliciform nets fastened with a metal ring which is necessary for installation of the disc on angle grinders. The fan of petals with an abrasive compound is glued to the frame with the help of epoxy adhesive. The product is intended for operation on a tool with rotary speed 12200 RPM.
Recommendations for the selection and exploitation of flap discs
It is necessary to pay attention to the following parameters to choose the right flap wheel for work:
- First of all it is, of course, the diameter. Usually these discs are created of the same type at 125mm. It is optimal for angle grinders.
- Look also at the rotary speed. If 12200 RPM is written on the disc it is not recommended to put it on angle grinders with 13300 RPM.
Type of the wheels depends on application. If you need to process ferrous metal with abrasive grit A40-A80, choose an appropriate disc. Its cost will be moreover less.