Name That Hardware

Hex-Head Screw

It’s been just more than a month since my backside found its way back into an editorial chair here at Popular Woodworking Magazine. We are about to wrap up the first issue since my return. That means the articles are in our binder and we read everything one additional time to make sure there are as few mistakes as possible before it goes to press then to you for your reading pleasure. (It’s your duty to find the one mistake we left in the magazine and that can only be accomplished if your read the entire issue from front to back.)

Reading binder is totally different for me this time around. My duties and responsibilities are different. But there are things that stay the same. As we read, we also discuss any concerns we find. Yesterday there were a few discussions, but the one that fascinated me the most was about hardware for a portable workbench top.

In the article text, the author, Christopher Schwarz, writes that the above-picture hardware is a hex-head bolt. Of course, with each round that label is challenged. We all call it a lag screw. Bob Lang and I say a bolt has a nut involved to make a connection and that a lag screw is what was used.

Via e-mail, Chris again defended his label and directed us to a home center to confirm – he used the term by which the piece was listed at the store at which he bought it. (The goal is to make it easy for readers to find the exact piece – be it screws, nails or drawer pulls – used in the article.) So check we did. Do you think you know the answer? Be careful.

Online at one store we found the terms “hex-head screw” and “lag screw” intermixed. At a second store, we found similar terminology and we found the hardware item pictured below.

Lag Bolt ?

Chris wasn’t wrong in how he listed the piece.

Is this what happens when store inventory is labeled by folks who don’t really know what the item is called? Or is this known as a hex-head bolt? Are the terms hex-head and lag, and bolt and screw interchangeable? Comments are open. Let’s hear your thoughts.

— Glen D. Huey

If you want to read about Chris’ portable benchtop, or try to find the one mistake we left in the magazine (ha), sign up now to make sure you get the upcoming issue in your mailbox (click here) or sent to your mobile device (click here). If you’re in Canada, click here. If you’re elsewhere, you need to click here.

67 thoughts on “Name That Hardware

  1. icmguy

    Here in the northeast we call them lag bolts. They’re usually used with “lead” shields to attach equipment or wood ledgers to concrete. So I suppose you could consider the shield to be the “nut” in the bolt assembly. The screw threads certainly grab the soft metal better than any other thread you might use. I expect it all boils down to how you use it. Perhaps the hex head is a redundancy since the majority of modern bolts have a hex head rather than the square (old) or twelve point(newer) you see on occasion.

  2. keithm

    I’ve always called them “lag bolts” It may be a regional thing like soda, pop, soda pop, coke, etc.

    Where it gets fuzzy is
    * Hanger bolt (half machine thread, half screw thread)
    * Dowel screw (double screw thread)
    * Dowel pin (a wooden piece cut to length, often spiraled or fluted)

    1. keithm

      …. Of course if you go to the big box store, it’s pot luck. I remember asking for a carriage bolt once and the guy behind the counter looked at me like I might be Amish or something. He had no clue. I related the story to my wife and she said, “I would not know what a carriage bolt is.”

      I replied, “Yes, but you don’t work in the hardware department at Home Depot.”

  3. tms

    I call it a lag screw.

    For me, a screw is held in tension by the contact of its threads to the wood. A bolt is held in tension by a nut.

    There is an old adage in wooden boat building:
    Nail where you can,
    screw were you must,
    and bolt where you have to.

  4. Jonas Jensen

    What does the American Standardisation Society call it?
    I agree with jmoorse, that a picture could be nice, but usually I am able to get an idea of the hardware when I go to the site you reccomend in the article.

  5. John Vernier

    Sounds like a decent topic for a short article. Isn’t Hillman group based in Cincinnati? Maybe you should do lunch with somebody over there and see if they have the same problems with different retailers or regional variant terms. FWIW growing up in Michigan these were always lag bolts, but I think the distinction between bolts and screws is a good one, and worth fighting for.

  6. brownkm52

    I’ve always called that a lag bolt. My after-the fact explanation:

    If you turn it with a screwdriver, it’s a screw.
    If you turn it with a wrench, it’s a bolt.
    If it’s a bolt with screw threads, then it’s a lag bolt.
    If it’s a bolt with a domed head and a nut, then it’s a carriage bolt.

  7. Bill Lattanzio

    A good rule of thumb may be that a screw can thread itself and a bolt cannot. Even so, one of my distributors calls it a hex lag screw, the other a hex lag bolt. So I can see where all of the confusion comes from.

  8. jmoorse

    That object is technically a hex head lag screw for wood. I buy mine from McMaster-Carr, whose catalog description shows the relevant ASME, ASTM and SAE standards. The nice folks at hardware and big-box stores aren’t technical experts and the signs and labels are often incorrect. I’m usually happy if they can tell a nut from a bolt. Don’t bother asking the guy in the tool department for a brace.
    The best way to make sure that your readers can identify the correct hardware is to show a clear picture of it. That way even those in other cultures, or whose first language is not english, can understand. While I love PWW magazine, I usually find your drawings incomplete. But that’s just me, an engineer but not a writer. I tend to improvise anyway.

  9. iwigle

    Interesting…
    In Canada I’ve always known these as lag bolts. And when I check the Canadian sites for Home Depot or Lowes, they call them lag bolts as well. If you search for lag screws, you find no lag bolts.

    No argument with the “bolt needs a second (female) device”, I agree with the discussion about “lag screw”. But this does raise a more generic editorial challenge: When something is properly called a widget, but virtually the entire world calls it a doodad, what’s an editor to do???

    1. Megan Fitzpatrick

      That was our concern exactly – do we use the term under which it’s sold (at some places) so that readers can easily find it, or do we use the term that we know to be correct? (Or, if space allows, do we parenthetically explain that some suppliers have it incorrect?)

      1. pmac

        Note to the editors: Call it whatt you want, but “a picture is worth a thousand words”. We all know what part to buy based on the above pic.

        As to the camp I’m in: a bolt requires a nut, a screw doesn’t..

    2. almartin

      Well, fwiw, if you search for “lag screw” on Lowes’ US website, the listing for lag bolts comes up. So you can get what you want even if the vernacular is different. The Home Depot page calls them lag screws (and searches for both lag bolts and lag screws end up on the same page.)

  10. Peter

    OK, to add more monkeys the barrel: fastenersaustralia.com.au calls this thing a ‘coach screw’ and wilkes.co.uk call it a ‘coach or carriage bolt’. Don’t think that helps!

    pete

  11. jrfuda

    I too vote “Lag Screw.” When you talk to folk in the construction trade, that’s what they call it. When you watch a DIY show where the seem to be building a deck every week on one or an other of them, they always talk about attaching the ledger with lag screws unless they have the ability to attach with bolts (access to the interior side where the ledger in mounted). I, personally, have used them most recently to attach my lumber rack to studs in my shop and to mount an antenna to the rear gable of my home. Both times I went looking for lag screws, not bolts.

  12. danoelke

    Its a lag screw (adding “hex headed” is optional). As you say – a bolt is threaded to have a nut put on it. While I know that terminology shifts over time – I think those who know that there is a better / more correct term to use have a duty to educate others.

    Edivince that some online retailers got it wrong is not a good excuse to further corrupt the language. There are other examples (probably many more) of retailers that get it right. To use Chris’s reasoning against him – if more & bigger retailers get it right, then more readers will find what they need by using the correct terms. I think you will steer more readers towards finding the right piece of hardware by using the right name. For example – Home Depot does get it right. If you search “hex bolt” you see bolts. If you search “lag screw” you see lag screws. And if you search for “hex lag bolt” you see lag screws – *and* the title for each item says “lag screw”

  13. jte9999

    I’m with you, Mr. Lang, and Bill. I’ve never heard of an ‘Archimedean Bolt’. A bolt is a fastener which requires a second part. That’s my story and I’m sticking to it.

  14. Bill Lattanzio

    If you want my two cents. That is a hex lag screw. Screws are tapped into wood or metal, or what have you. Bolts are fastened through using nuts or threads. I’m not just guessing blindly, I use and sell hardware for a living.

COMMENT