what is the difference between t27 and t29 flap disc

Some Factors That Cause The Cutting Disc To Break 1. The cutting disc is defective, not up to the line speed of the cutting table. 2. In addition, the cutting disc bore diameter and the cutting table shaft are not equipped, and there is a lot of stress during the assembly process. 3. When the tissue of the cutting disc is uneven, stress will accumulate in the weak part of the tissue, leading to breakage, as well as factors such as torsion, thermal stress, and tremor during the cutting process. 4. When the hardness of the cutting disc is too high, the radial torque force on the cutting disc will increase. Since the thickness of the cutting disc is usually less than 4 mm, the cutting disc will break. 5. When the resin of the cutting discs lacks toughness, due to the grinding wheel  is always under negative pressure during the cutting process, transverse stress will inevitably occur. When the cutting disc cannot resist the transverse stress, it will cause the grinding wheel to crack. 6. Work Improperly Clamped The work holder should be of proper design and of adequate size for the complete range of work for which the cutting-off machine is designed. If the work is allowed to shift or the pieces cut off do not fall away properly, the wheel may be “pinched,” this is a major cause of wheel breakage. If the bar or tubing cut is slightly warped it should be clamped in such a manner that the convex side is down and is in contact with the work support. Otherwise when the piece is cut off, the bar or tubing may drop slightly, “pinching” the wheel 7. Abusive Operation Cutting-off wheels are thin and do not have great lateral strength. Care should be taken to avoid twisting, cocking, cramping, or exerting any pressure on the side of the wheel.This is particularly true on portable cutting-off machines where the work is held and the wheel is guided by hand or on operations where the work is not clamped. On such operations only reinforced wheels should be used. Attempting to cut work beyond the capacity of the wheel or the machine may cause wheel breakage.