Antique Bayonet??

Thats a good old M1907 bayo - the S A with the "bomb" is the stamp for the Springfield Armory Arsenal (Springfield MA). As mentioned, it will fit the M1903 and M1 Garand rifles.

Its worth a good amount - I admit I don't have exact figures and am not an expert on bayonets. But, I'm pretty sure the original canvas scabbard adds significantly to the value, and if it is a 3-piece scabbard it is worth even more. (some people think a 3-peice 07 scab doesn't exist - I've seen and handled an original...but that shows you how rare they are)

If it is indeed in "excellent" condition, and is all original its a sought after collectors item. Some 16" bayo's were shortened and reissued. If you look at the history, bayonet designs have shortened over the years - 16" 1907 model was the last of the long ones in the US arsenal as far as I know. The issue bayo for the M1 Garand in WWII was 10 inches. For the M1 Carbine, M14, and M16 variants respectively, the issue bayonets were well under 10".

Your Bayonet is for the M 1903 Springfield Rifle, it will also fit on the M-1 garand Rifle. Yours is still in the original configuration as the blades were shortened to 12 inches on a number of them During WW II. Value to a collector in that condition would be in excess of $75