Relief grinding? What’s it all about?

Posted on November 11, 2013 at 4:45 PM

Steve Wilson, Bernhard Business Development Manager for Pacific Asia puts relief grinding into perspective.

During the last 14 years, I have worked and travelled across Asia visiting hundreds of golf clubs. This professional experience is augmented by a childhood spent on my parents’ golf course in Canada. Over the many decades I’ve spent in and around golf, I have heard countless discussions and arguments for and against the importance of relief-grinding. The question I’ve always had is “Why?”

There are four surfaces of interest on a cutting reel.

1) Front face of bedknife

2) Top face of bedknife

3) Relief ground area of reel

4) Spun ground edge of reel

Of these four surfaces which do you think is the most important? For that matter which is the least important?

These are questions not often asked or discussed, so I’d like to explore them here to help put relief-grinding in proper perspective.


Of the four surfaces there is little doubt the bedknife front and top face, as well as the spun ground edge of the reel, are the “working” ends of the mower. This is where the “cut” happens so if those edges are not super sharp, the grass will be torn and damaged.

Relief-grinding occurs at the rear of the blade and, therefore, has nothing to do with the actual cut of the grass. When you have a quality of cut issue and you only relief-grind, turf health will not improve. To enhance the quality of cut you must sharpen the bedknife front and top faces, plus the leading edge of the reel (spun-ground).

To this day there are UK and Australian reel mower manufactures that produce high-quality reel mowers with a flat grind (zero-relief). These mowers can produce a quality of cut every bit as good as reel mowers with ground-relief.

Throughout my career as a superintendent in Canada and Japan, I worked with countless golf courses. Some only spun-ground, while others spun and relief-ground reels. There were spin-only courses with great turf and there were spin/relief courses with great turf. What provided the magnificent cut were sharp edges on both the reel and bedknife. The relief-grind played no role in cutting the grass cleanly.

Now there are likely some of you screaming, “Steve Wilson doesn’t believe in relief grinding reels.” I’m not saying you shouldn’t relief-grind. Instead, I’m advising a diminished emphasis on its importance as it relates to turf health.

If you backlap, then you need to relief grind (and I would say get a faster spin grinder!).

But the relief-grind is the least important of the four surfaces. You should be focusing 80% - 90% of your efforts on the bedknife front and top face, and the spun-ground tip of the reel. The remainder of your grinding time should be spent on grinding-relief.

Relief-grinding can provide some mechanical benefits but they are far less important to cutting the grass cleanly. As we all know, we are in the business of growing and maintaining disease-free grass so that is where we should focus the majority of our efforts. If we cut grass cleanly it will be healthier and cheaper to maintain. Moreover, because surveys have revealed “outstanding conditions” are a primary determinant in golfer satisfaction, it also means increased revenue for your course due to more frequent play.

If you believe in both spin and relief-grinding, go for it.

If you believe in spin-grinding only, that works too.

With a properly configured cutting unit, both techniques can produce great turf. But a sharp reel is a prerequisite to cutting turf cleanly. Therefore, we must focus 80% - 90% of our efforts on the leading edges of the bedknife and reel, not grinding relief.

So again I ask why so much talk and discussion about grinding relief? We should be talking more about the front and top faces of the bedknife and the spun ground tip of the reel. This is where grinding can make a marked difference in turf quality.