In 1973, the National Knife Collectors Association developed a knife grading system that became the standard for many years. Over time, most dealers and collectors have enhanced the standard to provide more clarification and a more detailed grading system. Most knives are now graded as described in the table below.
This condition is perfect plus. Knives in this category must be flawless, and must have additional characteristics that set them apart from mint. They could have an unusually good fit for example.
This would be a knife that has never been carried, never sharpened, never used, and does not have rust problems of any kind. Some collectors will classify a very old knife that has a few rust marks as mint (especially those made prior to WWII). The newer the knife gets from there, the less rust specs it must have to maintain its mint status.
In addition, most Case knife collectors are a bit more strict on grading knives. An old Case knife with any rust mark would not be considered mint. Note: A knife that had rust, and was cleaned to look mint would be considered near mint or worse depending on how harshly it was cleaned.
There must be nothing wrong with a near mint knife. It should "walk and talk" and must have most of the original polish visible on the blades. Very light sharpening would be acceptable, but the blades must be full. It can have some light rust spots, but no deep rust pits. Some light carry scratches are permitted on the outside as well.
Knives in this condition would constitute a solid, lightly used knives. There may be a bit of blade wear (no more than 10% on any one blade), and some tarnish and light pitting would be acceptable. Blades should still snap well, and the tang mark should still be clear.
Knives in this category are generally fairly well used knives. There may be blade wear of up to 25%. The blades should still be sound, but one or more may be slow. The stamping should be readable, but may be faint. The handles may have cracks and wear, but shouldn't have major chipping. The knife might also have some rust pitting and tarnish.
Knives in good condition must still be useable as a working knife. Blade wear may be between 25-50%. There might be chips in the handle or blade. Blades may be slow with deep pits and rust. You should still be able to make out the maker of the knife by shield or tang stamp.
A poor knife is generally only good for parts. The blades might be less than 50%, extra lazy or even broken. Tang marks are generally barely legible, and the handles may be chipped.
Anything less than poor. These knives would be pretty much worthless. May have a liner, back spring or bolster that would be salvageable for parts, but probably not even that.
What does new, used, vintage and antique knives mean?
New knives: Never sold to a customer and never used. New as shipped by the manufacturer or distributor with all original packing (box, sheath, etc.) and instructions. Knives or any merchandise sold as "New" must be eligible for full warranty service from the officially authorized importer, distributor, or factory in the USA. New is what most knife stores sell and they are generally current production knives.
Used knives: Any knife that has been owned by a customer, even if it is like new. Used knives may not have the sheath, accessories or box that they came with. They vary in condition, from like new to completely worn out. By this definition most knives are used, including vintage and antique.
Vintage knives: Knives made after World War II (1945), but not still in production. They are no longer made. A vintage knife will usually be higher in cost than when it was originally produced, but many times it will not cost any more than a similar made knife today if you can find one.
Antique knives or Old knives: Any knife made before World War II (1945).
All Comments are Welcome and Appreciated.