2 Inch Bristle Disc,6 Pieces Roloc Bristle Disc Grade - 120# 80# 50# Grit Abrasive Coating Removal Disc for Metal with 1/4 Inch Shank Attachment

The block is cast iron. The heads are aluminum. The mounting surface must be as clean and free of any debris. I used the green on the block surfaces and heads. They both came up mirror clean without any markings, scratches or grooves. Definitely a great tool for engine builders and gasket removal.

They work and last better than expected.

The first bristle disc I used lost nearly half its bristles within 30 seconds of use. The bristles should be more pliable, but are too brittle and break off too easily.

Very poor quality and does not last long.

I purchased these to clean up weldspatter as a machine builder. These are garbage.

Es para mi novio .

Spend the extra money and buy the 3M brand, these suck and bristle start flying off and they leave a residue on surface.

I like that they remove the gaskets on aluminum heads and blocks

I purchased these to remove an oil pan gasket on a Triumph TR4 that was installed approximately 6 years ago. These disks would barely touch it. Found an old yellow 3M disk in one of my cabinets and within 40 minutes the gasket and sealing residue was removed. Very disappointed and in my opinion a waste of my money.

I purchased one 3M brand from NAPA auto parts and it worked great (120 grit - white) but was too fine and taking too long. I also purchased these which included 2 white (120 grit), 2 yellow (80 grit), and 2 green (50 grit). After using the Green from this set, they both wore out and didnt clean as good as the 3M white one from NAPA. I actually went through 1 white, 1 yellow, and 2 green, and STILL had to go over everything with the 3M white from NAPA to clean it all up. That 1 outlasted 4 of the more course grit sanding discs from this kit, and it is supposed to be the finer grit! I am requesting a full refund as my project is not done and now will be purchasing the actual 3M discs to finish my project (2 heads and engine block head mating surface).