Reamer Replacement vs. Reamer Sharpening
According to Sonnax Industries, “A dull reamer will cut a smaller hole. Reamers can be sharpened, but should only be done by a professional tool sharpener. Actual life of a reamer before resharpening or replacing averages 50-70 bores.” The replacement cost of a new reamer may be worth the time and effort you must expend to re-sharpen your existing reamer.
The flutes—or grooves—of a reamer can be straight, spiraled or expandable (expandable for regrinding). Using a honing stone made to sharpen reamers, such as Norton Reamer Sharpening Stones, you must stone the face of the reamer blade rather than the top edge, according to Brownells, an Iowa company that provides brief reamer sharpening instructions with accompanying illustrations at brownells.com. “While grinding, each tooth should be ground to the same extent. Fast and heavy grinding should be avoided, as it results in grinding cracks that are microscopic in nature,” notes H.S. Bawa, author of Manufacturing Processes.
To achieve a good result, your most practical option may be to leave the reamer sharpening to the professionals, especially for spiral reamers, unless you have a tool and cutter grinder. Most grinder machines employ computer programs and are highly automated, allowing them to perform complex grinding operations.