Today we look at the differences between Type 27 and Type 29 Flap Discs and Type 1 and Type 27 Cut Off Wheels
What is the difference between a Type 27 and a Type 29 Flap Disc?
A Type 27 flap disc is referred to as a flat disc. It is best used at a 0-15 degree angle. Type 27 is used for grinding the plane and outside corners. In the bucket program we see lots of Type 27 discs used only on the edges so the recommendation is to switch to a Type 29 disc.
A Type 29 flap disc is referred to as a curved disc. It is best used at a 15-25 degree angle. The grinding surface of the curved flap disc, Type 29, has an upward curvature, allowing it to grind at a steeper angle. It is mainly used for grinding of corners and edges. When speed and cutting ability have higher requirements always recommend the Type 29.
What is the difference between a Type 1 and Type 27 Cut Off Wheel?
A Type 1 Cut Off Wheel is a flat wheel used on the edge. The number one drawback to this disc is the exposed mounting hardware that does not allow a flush cut but allows cutting all the way down to the mounting hardware. The Type 1 will give the maximum number of cuts and is usually the cheapest to buy. It must be used at a 90 degree angle, any deviation from this will result in breakage, which happens frequently.
A Type 27 Cut Off Wheel is often referred to as a depressed center wheel. The mounting hardware is in the depressed center, allowing for flush cutting. The Type 27 Cut Off Wheel must be used with an appropriate guard and a depressed center back flange. The center hub protects the user from cutting too deeply. The hub also allows for avoiding reinforcement wear and for extra rigidity for additional safety. The Type 27 produces 20% less cuts than the Type 1 on average.