Markings are LW with some sort of symbol and then 15. Then on the underside of the hilt is marked the following: LFM 45 484.

I've included some pics below. This sword/bayonet has a blade that is roughly 15 inches in length and is quite thick.

Any help would be most appreciated.

This is an Austro-Hungarian military issue of WWI, pioneer's M1915 side arm or short sword.

Thank you so much for identifying this tool. And it seems more of a tool than a weapon to me.

Any idea what the LW mark would stand for? Maker? Just curious.

Again, most appreciated. I found it in my grandfather's closet. He passed away a while back. He was a medic in WWII and saw several beach invasions. "Invasions 'R' Us" was what his company was called apparently. I wonder how he came to have this short sword.

LW do probably stand for the maker - there were several contractors as usually happens.
It is a tool, used to clear off firing posts, making saplings for the trenches - and could be employed as a fearsome weapon within the close quarters of the trenches. It may have been used also in WWII by an axis soldier and this way your grandfather got it.

Hi,
interesting! It looks like a bauerwehr (with no nagel), good old recipes... ;)

Nice piece you have!
LW is an acceptance mark commonly found on period military equipment, especially swords: L??? Wien. This is a less common variation of the M1915 pioneer sword sometimes wrongly called M1916. The difference between this and the common M15 is the curved grip similiar to the M1853.
It was introduced during WWI to replace the more expensive and elaborated M1853 and used by the Austro-Hungarian technical troops like pioneers and sappers. For it's size it's quite heavy and clumsy, not good as a weapon neither as tool... well a small axe is better.
The makers mark should be on the other side of the ricasso, but there are several unmarked pieces. The most common makers are: Zeitler - Wien, R - Rasicka(?), SR with cross - Simon Redtenbacher, Zelinka - Budapest. The LFM it's an unit marking, not sure what it means, but someting like Landfeldm....
Many of my ancestors served in the A-H army, so I have a small collection of period items.

Yeah, I looked over the short sword again. It really only has LFM45 underneath the guard with a 484 stamped underneath the LFM 45.

Then on the blade, it has LW w/what looks to be an eagle crest with 15 stamped after.

I looked at some examples on line that have different markings than the one I have. It's such a brute of a weapon, I must say. It's primitive and the thickness of the blade amazes me. I have been unable to find a pic on line with the same markings as the one I have. I guess that doesn't mean it's rare or anything, but still has me a little curious.

Thanks!

Well, the blade is very sturdy, about 7 mm thick and you can literally split bricks without any damage to the blade. The quality differs from maker to maker.
Nothing special with the markings, the LW is a very common austrian acceptance mark and the unit marking depends on the military unit in which it was used. Ex. FHR 23 = 23th Feldhowitzerregiment. The other 3 cyphers form a serial number to keep evidence of the weapon.