Hi Ray,
I would have thought a professional sharpening chap would first ask what you intend to use
the mower for before recommending a 5 degree angle, unless he is recommending a 5 degree
angle to make more profit from more regular sharpening.
For Home use I'd go with the blade being ground square for a longer lasting reel and less cost.
In a professional environment, when cutting high-maintenance lawns, such as putting greens or lawn bowl greens, a 5-degree angle on the reel can indeed provide a sharper edge, potentially leading to a cleaner cut initially. A keener angle can improve cutting performance but may result in faster dulling, particularly if the mower is used frequently or on tougher grass types. This may require more frequent sharpening and maintenance.
Durability vs. Sharpness: A square edge may be more durable over time, which can be particularly useful for residential lawns where the grass isn't overly tough. If you are cutting more resilient turf or using the mower frequently, the choice may vary.
If you prioritize an initial sharp cut and are willing to maintain the blade more frequently, a slight angle could be advantageous.
A few tips for maintaining high-maintenance lawns below link.
https://www.lawnsforyou.com/fine-turf/definitive-guide-maintaining-bowling-greenCheers
Max.
