If you look at many varieties of moulding available at Home Depot, you get descriptions like:

WM 376 -11/16 in. x 2-1/4 in. Primed Finger-Jointed Door and Window Casing Moulding

Any idea what these WM letters mean (eg. LWM, WM, WG)? I have a few bad guesses:

I thought the WM might be "Window Moulding" - but WM can be used in crown moulding and other non window related uses.

I thought the WM stood for Woodgrain Millwork, but Alexandria moulding also has the WM.

I thought the M in LWM and WM was for the MDF, but sometimes the MDF pieces don't have either of the 3 common acronyms.

I thought the WG might stand for Wood Grain but many WG boards can be made from MDF.

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    Great question. The model numbers for the profiles have to originate somewhere. This answer may be lost to history, but I'm interested.
    – JPhi1618
    Commented Nov 15, 2019 at 16:14
  • Are you more curious because you love quirky pieces of backstory and technical knowledge (like I do)? Or for the benefit of clarity?
    – Jon Crosby
    Commented Nov 25, 2019 at 5:09
  • @Jon Crosby Both. Blindly buying products like people do, tossing instruction manuals, and then the typical construction worker being baffled at failures in what they've built is mostly from chronically never thinking. Sometimes I discover pointless pieces of trivia going down these rabbit holes, and sometimes I discover some mind blowing stuff. If Forest Gump built houses, "Construction theory is like a box of chocolates..." ;) Commented Nov 25, 2019 at 15:57

3 Answers 3


Thanks for clarifying your motivation behind asking. If your goal was to learn a universal nomenclature of moldings, I was bringing bad news:

My 25 years of directly related experience has uncovered no such uniformity. The only way to clearly and universally designate moldings is by function.size, and description of profile. For less common items and large orders, a builder is wise to approve full scale rendering or physical sample.

Alpha designations for moldings [in my area] are unique to the mill that cut them. If commonality exists beyond that, it goes unnoticed, especially in the field. There are a few numbers that are widely repeated, though I haven't found anyone that knows their origin; even at the big stores, you'll find "356" and "444" casing.

in a given locale, it's usually understood what is expected to be in a house, and it's reflected in the limited variety of locally available stock. A deviation would simply be specified by its difference, e.g., "flat" casing; "3 bead" screen. As is typical in trade terminology, there will also be some regional variations in common terms. Around here you'd hear "speed base" to refer to the contractor grade mdf ogee baseboard.

Overall sizes are pretty standard (though called on both nominally and diminsionally), as are some shapes (though sometimes described instead of named). Basic crown molding are 2⅝", 3⅝", 4⅝", etc." Colonial "(traditional) or *cove" . Typical baseboard is 3½", 4½", 5½", etc "Ogee". Perhaps it's "base with cap".Casings are 2¼", 3¼", 4¼,, and may be called by "flat", "2-step"/"3 step,." Shelf edge", or nosing, is screen mold, "flat", "2-bead", or "3-bead".

Of course, all of this is period relevant, both in terms of style and nomenclature. Not long ago, "base and case" was interchangeably used to trim "doors and floors".

Anyone in the business of dealing with these products should be able to communicate through description using basic profile features such as cove, bead, shoulder, flat, thumbnail, etc. Additionally, some shapes have several variations, like the Ogee. They're based on academically recognized architecture styles.

These are just some examples. Should be at least as clear as mud! I know it doesn't answer your specific question (as I don't know that it has an answer), hopefully it is helpful in some capacity.

Im always interested to learn the experience of others. Perhaps we might find some evidence of a more universal rsal commonality!

  • Hello, and welcome to Home Improvement. Great answer; keep 'em coming. And, you should probably take our tour so you'll know how best to contribute here. Commented Nov 30, 2019 at 17:56
  • Thanks for taking a moment to give an answer on this! While I think this answer is pretty helpful, but as you mentioned, I'm not sure it gives us the precise answer to "what do the letters mean" in the description. Granted, maybe there's no answer. The other answer here thinks the WM is just a typo, this answer here states the numbers have no real known origin or meaning, but finally this answer doesn't really address what the letters mean and/or their origin other than the letters aren't universal. If these claims are correct, it's quite shocking to see such garbage in all the descriptions. Commented Nov 30, 2019 at 20:49

Nope. There are more letters, less letters and lots more with no letters at all.

Though, you were quite correct when you guessed WM stood for Woodgrain Millwork. The LWM is for their "Linear" moulding product line and WG is for their Wood"guard" product line. Scroll about 2/3rds of the way down on their Home Page to see more on their product lines at https://www.woodgrainmillwork.com/

However, you won't find any of the Home Depot letters on their website nor any others, as they just go by the number...if you're lucky. Like 254 works in a search, but any variation of WM254 yields no search results.

Alexandria Moulding sharing a WM is a typo or leftover from when Woodgrain used to supply that moulding. Alexandria actually lists their product as 0W254 (I think, that might have been for 205).

Now, if you think - "well then I can go with the number". Nope again. Manufacturers don't really share much there either. Yes, depending on what you're looking for being a basic shape, then it may be a 254 or 205 with another maker.

The only commonality between all manufacturers is the shape or traditional name and use. Like: Astragal, Crown, Base, Shoe, Corner, Brick, etcetera...Alexandria has a Visual Glossary at http://www.alexmo.com/?page=visual_glossary But, makers can be small in selection or huge. The small ones don't do basic shapes and are very snobbish of build-up or stacked mouldings.


I suspect it’s an inventory identification code used by Home Depot. The letters are not “common” letters used throughout the construction industry, such as: VG, PT, etc.

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    Actually those designations are used by pretty much everyone, not just HD. There was an old old book I had a copy of once, called "General Requirements for Wood Mouldings" that I think originated back in the colonial days (mine wasn't that old, maybe from the 1940s). I can't find it any more, but I'm going to bet that's where those designations originated from. It basically described all kinds of different moulding patterns available over the years, it was a must-have book for people doing renovations of old homes needing to match old existing millwork. Try finding a copy of that.
    – JRaef
    Commented Nov 15, 2019 at 1:39
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    @JRaef Those letter designations are not common in the construction industry. The OP is trying to determine what the acronyms mean. Try asking any carpenter what the difference is between a LWM 623 and a LWM 47 and they won’t have a clue. However, ask at Home Depot, and they’ll know exactly. (If “those letter designations are used by pretty much everyone “ as you say, try Googling LWM meaning” and see what you get.)
    – Lee Sam
    Commented Nov 15, 2019 at 22:00
  • Back in the day, it was the initials of the mill that cut the profiles, or so I thought...
    – Jack
    Commented Nov 16, 2019 at 3:43
  • @Jack - I thought that too, but then I noticed the same letters (eg. WG - WoodGrain?) would transfer over to non WoodGrain moldings so it led me to believe this isn't the case. Commented Nov 17, 2019 at 15:57
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    When I was coming up in the trade back in the 70's and 80's on the east coast, I am certain the list of moldings and their profiles were on the counters of the local lumber suppliers. The name at the top who provided the moldings, if I remember right, coincided as if they used their initials for the beginning of the molding number. The profiles have become so common place that the letters simply stayed. I can only say that for the LWM and WM, possibly MM. The others, who knows. For some reason it brings to mind 6010 handrail. Very popular handrail profile, but a number of producers supply it.
    – Jack
    Commented Nov 17, 2019 at 16:35

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