The digital angle gage is a very handy little tool around the shop, but especially at the sharpening bench. Precise angles for plane irons and chisels are not as important as some would lead you to believe. However, sharpening to a consistent angle is very important. When you can consistently sharpen your edge tools, to whatever angle you have found to work the best for you, your edge tools will perform consistently time after time.
The digital angle gage allows you to set your honing guide to whatever angle you choose within plus or minus o.1 degree. The only problem with these gages is their width won’t allow them to be used for chisels.
There are several brands of digital angle gages available. They are priced around $40 USD, but you can often find them on sale. I bought mine for $30 USD.
Oh! Yes I do use a honing gage for tool sharpening and I recommend them, but that is another article.