How to Use a ring file

What recommended sand paper to file away burs from the piston ring??

Hello, you will need very fine sandpaper example would be 1200 grit wet and dry or finer. I prefer to use a file similar to a nail file.

Regards Ross

Do you mean the very slight ridge that sometimes is left when the ring has been filed'ground for the correct end gap, or the best grade of abrasive for the actual end gap material removal?

As Ross said, for the first, usually a very fine file is used, but some rings are made of steel and may be harder to file. Another option some use is a fine, hand held whet-stone, or abrasive block, such as these

https://nz.rs-online.com/web/p/sharpening-stones/0827732/?cm_mmc=NZ-PLA-DS3A-_-google-_-PLA_NZ_EN_Hand_Tools_Whoop-_-(NZ:Whoop!)+Sharpening+Stones-_-827732&matchtype=&pla-340818750218&gclid=Cj0KCQjwkIGKBhCxARIsAINMioJ59WDrzVWwhC8YDFi_AwGVt4JieWDljCJSklj2ly9EGuz6pGcDAz4aAgc5EALw_wcB&gclsrc=aw.ds

https://nz.rs-online.com/web/p/sharpening-stones/3156128/?cm_mmc=NZ-PLA-DS3A-_-google-_-PLA_NZ_EN_Hand_Tools_Whoop-_-(NZ:Whoop!)+Sharpening+Stones-_-3156128&matchtype=&pla-307145821850&gclid=Cj0KCQjwkIGKBhCxARIsAINMioI8WLzg77-s3LEvsbDEI32xgfpIH6vzqj2pjFnKc4oovKmdvnTEG8EaAlNrEALw_wcB&gclsrc=aw.ds

Take off the minimum material - if you can see the tiniest chanfer, that's enough, and because some rings use a surface coating, move from the outside to inside to minimise the chance of chipping.