Coin Grading Unravelled
Graded and slabbed coins have become increasingly popular with collectors in recent years. When purchasing such pieces it can be important to know how the assigned grade compares to other grading standards. Both the US and UK numerical grading scales have been created to apply to milled coins, the US scale being based on a modified 70 point scale derived from Dr William Sheldon's original 1949 scale to grade early American cents, and the CGS UK scale specifically intended for English milled coins. Both grading scales work acceptably well for British milled coins but there are significant differences between the two and with the standard terms used for grading British coins. A comparison between the scales and standard terms is given below.
There are now also a reasonable number of hammered coins graded and slabbed by US grading companies, but it is our opinion that slab grades can be somewhat misleading when used to grade hammered coins. The reason for this is that hammered coins were typically produced on hand made flans and were hand struck meaning each coin is has individual characteristics of it's own. Words and images can far better describe a grade for this type of coin than a number, as flan shape, double striking, weakness etc. should all be taken into account. Furthermore, hammered coins should always be weighed as significantly underweight coins can be identified as being clipped but when a coin is slabbed and graded by a third party, the weight does not usually appear on the slab. The British hammered series of coins can be a complex one and it is important to have a good understanding about a series of coins before attempting to properly grade them.
Before a comparison between the grading scales can be made we must first look at the scales individually. An explanation of the standard grading terms typically used to grade British coins and used by AMR Coins can be found on our Coin Grading page.
The 70 point scale used in the US does not use all of the 70 grading steps. The 'Mint State' designation is supposed to apply to coins with no wear, but an MS-60 coin can have marks, edge nicks, hairlines etc and would not typically be considered to be uncirculated by UK grading. One description of the steps often used are given below, though the descriptions sometimes vary.
|The type is barely discernable, but little else, due to the coin being badly damaged or worn smooth
|Type and date are barely discernable, but otherwise the coin is damaged or extremely worn
|Type and date are discernable, although some spots may be worn out. Some lettering should be apparent and readable
|Major devices and features are evident as outlines. although the coin overall is heavily worn, lettering nearly full
|Rims complete with flat detail, peripheral lettering full
|Full rim with clearly discernable devices and features. Most legends are readable clearly, but the whole coin is still significantly worn
|Design worn with slight detail, slightly clearer
|Distinct rim, all legends readable, clear devices showing some detail, but the whole coin is moderately, but evenly worn
|Slightly more detail in the recessed areas, all lettering sharp
|Clearly readable but lightly worn legends, devices show good detail, rims are clean, but the whole coin shows moderate wear
|Slightly more definition in the detail and lettering
|Almost complete detail with flat areas
|Detail is complete but worn with high points flat
|Legends are sharp, devices are clear with slight but obvious wear on the high points
|Detail is complete with some high points flat
|Full detail with friction over most of the surface, slight flatness on high points
|Full detail with friction over 1/2 or more of surface, very slight flatness on high points
|Full detail with friction on less than 1/2 surface, mainly on high points
|Full detail with only slight friction on the high points
|No wear but may have many heavy marks/hairlines, strike may not be full
|No wear but with multiple heavy marks/hairlines, strike may not be full
|No wear but slightly less marks/hairlines, strike may not be full
|Moderate number/size marks/hairlines, strike may not be full
|Few marks/hairlines or a couple of severe ones, strike should be average or above
|Minor marks/hairlines though none in focal areas, above average strike
|Few minor marks/hairlines not in focal areas, good strike
|Virtually as struck with minor imperfections, very well struck
|Virtually as struck with slight imperfections, slightest weakness of strike allowed
|Virtually as struck with minuscule imperfections, near full strike necessary
|As struck, with full strike
The 100 point UK numerical system used by CGS originally had an associated grade alongside the numerical value, but this has recently changed to give a numerical only grade. Like the US scale not all of the values are used.
The table below shows how one scale relates to another based on our grading using standard terms, and our experience and observations of the numerical scales. It should be noted that the prefixes accompanying the US grades typically imply a higher grade than the UK grading terms (e.g. AU = VF-EF).
|MS66 - MS70
|MS64 - MS65
|MS62 - MS63
|MS60 - MS61
|AU58 - MS60
|VF35 - EF40
|VF20 - VF30
This should be taken as a guide as comparisons between numerical grades can de difficult due to the way the different scales are used. A Sheldon scale MS60 may not have been in circulation but it will have certainly been mishandled and many would argue that a very lightly circulated and well treated coin would be preferable.