The M1 Garand rifle was adopted by the US military in 1936-37, however actual production was very limited prior to the onset of World War II. Developed at Springfield Armory by designer John Garand, a Canadian employed at the oldest US Government arsenal, more than 6 million M1 rifles were produced. During WW2 the manufacturers were Springfield Armory and Winchester firearms. During the Korean Conflict additional production was ordered from Harrington & Richardson Arms and from International Harvester Company.
The original design of the M1 rifle specifically allowed the use of the M1905 bayonet then issued for the M1903 Springfield rifle. The M1905 was manufactured between 1906 and approximately 1930, and keeping it in use with the new rifle was undoubtedly a cost-saving measure during the Depression years. The M1905 was manufactured by both Springfield Armory and Rock Island Arsenal and can be identified as follows: 16-inch blade with single-stopped fuller (blood groove) along each side of the blade, single edge with short false edge on the upper edge of the blade at the front; blued steel finish, walnut grip panels, markings at the ricasso included maker's initials (SA or RIA), US Ordnance Deparment "flaming bomb" proof marking, year of production, and a serial number.
On December 7, 1941 the Japanese struck US Naval forces at Pearl Harbor in Hawaii, resulting in declarations of war against first Japan, then the German Axis forces. Contracts were let for massive production of war materials, including M1 rifles and new bayonets for the new rifles, which were designated as the M1942. Essentially a copy of the M1905 design, the M1942 was also a 16-inch blade but featured a phosphate anti-corrosive finish (Parkerizing) and black Bakelite (an early plastic) grip panels. Markings at the ricasso included maker's initials (contractors included Utica Cutlery "UC", Union Fork & Hoe "UFH", American Fork & Hoe "AFH", Wilde Toole "WT" and perhaps a few others), the "flaming bomb" ordnance proof, and year of production (all I have seen were 1942, but I have heard reports of some 1943 production).
Also, during the ramp-up of World War II production, existing M1905 bayonets were sent out to be arsenal-refinished which included new Parkerized finish and new Bakelite grip panels. All original markings were left intact. These are commonly refered to as the M1905/42 series.
In 1942-1943 the Ordnance Board decided that a 10-inch blade bayonet was advantageous for various reasons, and two things then occured. First, existing stocks of M1905 bayonets (as well as more than a few brand new M1942 bayonets) were sent out to contractors to be shortened to 10-inch length, Parkerized, and fitted with Bakelite grip panels. These were designated as the M1905E series (more below). Second, orders were sent out for production of a new 10-inch bayonet, designated as the M1 series (more below).
The M1905E series involved three basic identifiable variations. There were two basic production cycles, commonly refered to as "first issue" and "second issue" series. There were also two different styles of blade point produced in cutting down the older 16-inch blades to the new 10-inch length.
The "first issue" production included both blade point styles, and "first issue" M1905E's can be identified by markings. The original markings on the ricasso (manufacturer's initials, ordnance bomb proof, original production year, and serial number) were left intact, and the contractor performing the alterations placed their marking on the upper tang between the grip panels (most commonly seen will be "AFH" for American Fork & Hoe and "UFH" for Union Fork & Hoe). The two point styles seen are the "beak" style, commonly refered to as the "Bowie" point, in which the cut down process involved a single sweeping radius of the lower blade edge upward to the straight spine of the blade, and the "spear point" in which both the upper and lower edges were cut in a radius to meet in the middle of the blade. The "beak" or "Bowie" modification is most commonly refered to as the M1905E, while the spear point is most commonly refered to as the M1905E1. Both can be clearly identified by the fuller (blood groove) continuing through to the point of the blade.
The "second issue" production included only the "spear point" style, and can be identified by changes in the method of marking. The original stampings on the ricasso (original manufacturer, serial number, etc) were ground off and the ricasso was re-stamped with the altering contractor's initials (UFH, AFH, Oneida Limited "OL", and Utica Cutlery "UC" will be the most commonly seen), ordnance bomb proof, and "US". No production year date will be seen. These are also refered to as the M1905E1.
Probably in late 1943 production of the new M1 model began. The M1 can be identified by a single-stopped fuller on each side of the blade, ending about 3" from the point, and ricasso markings of "US", production year (almost all seen will be 1943, after which the year was not stamped), ordnance department "flaming bomb", and some will also have the circular War Department stamping. Manufacturers included AFH, UFH, UC, OL, and Wilde Toole "WT".
The M1 and M1905E1 series remained in general issue following WW2 and through the Korean Conflict until the mid-1950's. New production during that period is not known to have occurred.
In the mid-1950's a newly designed bayonet for the Garand rifle was adopted, known as the M5 series and featuring a 6-inch spear-point blade with a sharpened upper false edge, newly designed handle with a new mounting mechanism that eliminated the muzzle ring in favor of a stud fitting into the gas cylinder plug, and checkered black plastic grip panels. All were "Parkerized" finish, a dull gray-black phosphate coating. Markings were on the guard and included "US", the series "M5" or "M5A1", and the manufacturer's name (Aerial, Conetta, and perhaps a few others). The M5 series remained standard issue through the early 1960's when the M1 rifle was replaced for active duty forces, briefly by the M14 and then by the M16 rifles. Many National Guard and Reserve forces remained armed with the M1 Garand and M5 bayonets well into the 1970's.
Other bayonets seen for the M1 Garand rifle include those produced in South Korea and several NATO countries (Denmark, Italy, and others where the M1 rifle had been standardized as a service weapon).
Korean production included both the M5 series and a final modification to the venerable M1905 series. Some M1905, M1905/42, and M1942 bayonets were once again reduced in length to nominal 6-inch blades with spear point and reduced width overall, and the typical black Bakelite grip panels. The Korean arsenals also produced M5 series bayonets which can be identified by the "K" prefix to the model designation.
Danish production was a direct copy of the M1 bayonet series, differentiated only by the Danish Crown markings and arsenal initials "FKH".
Italian production consisted mostly of altering existing US M1 bayonets by fitting a new guard having a larger muzzle ring to fit the flash hider of their BM59 rifle, developed as a 20-round 7.62mm assault rifle conversion of the Garand design by the famed Beretta company.
M5 series bayonets were also manufactured in several European NATO countries, and can generally be identified by markings on the guard or ricasso.
This pretty well summarizes the evolution of bayonets for the M1 Garand rifle, and can serve as a guide for the beginning collector. There are several excellent books, and numerous collector web sites, that will offer additional detailed information and can be helpful in determining actual values for specific makers, models, and existing condition of specific pieces.
Millions of these relic bayonets remain in existence, and are an interesting field for collectors. Arguments over differing variations and markings are common, but especially confusing to the beginner. First bayonet for the M1 Garand? Well, the existing M1905 was the first, but already in unit inventories when the rifles arrived. First bayonet designed specifically for the rifle? Probably the M1905E1 series, but those were simply modifications of the 1903 Springfield's bayonet, so maybe the M1 (also essentially a modification of an earlier design) or the M5 series. Argue the point any way you like!
I have written this from memory, rather than consulting references, so there will be several omissions that the experienced collector will find. This is considered more as a "primer" for the beginning collector rather than as a definitive work. I hope many will find this helpful.