Chris Schwarz's Blog

How to ‘Time’ or ‘Clock’ Your Screw Heads

First a warning: Don’t read this blog entry if you already obsess too much over the details of your furniture. This entry could only make things worse.

Years ago, a high-end finish carpenter infected me with a disease for which there is no cure: clocking your screw heads. What is “clocking” – sometimes called “timing?” This is when you get the slots in all your screw heads to line up, either horizontally or vertically.

This carpenter pointed it out to me on a job he was working on. When he installed switchplates or hardware on cabinets, he always clocked the slots and said it was a mark of good workmanship. Since that day I have always looked out for clocked screws on furniture and cabinetry and have clocked my own screw slots when they are visible.

It’s a fairly uncommon feature on furniture, though it is common in other trades. I’ve met gunsmiths who clock all the screws on high-end firearms. I’ve also seen it on nice astronomy equipment.

So how do you do it?

Well there are lots of methods – enough to write a 10-page article on. When you are driving machinist’s screws into metal you might even use special screws designed for this. The head of the screw comes too tall for the hole. So you drive it in and mark where you want the slot to go. Then you remove the screw, file the head flush and cut a new slot with a hacksaw.

There are also ways to clock screws by machining the underside of the screw head.

In woodworking, you don’t need to go to those extremes to clock your screws. The way I do it is fast. It adds only a few minutes to installing a piece of hardware. But before I show you how, let me stress that this is not something I recommend you necessarily do in your furniture. I get obsessed about hardware and I might have mild OCD. That said, here goes.

1. Do all this before you color your hardware (if you are going to color it). This process can remove some of the color from your screw countersinks.

2. One method that some people recommend is to drive the screw, then remove it and just drive it again. This method doesn’t work well for me. I don’t want to cross-thread the wood and potentially weaken the screw’s grip.

3. So what I do is to drive in the screw and note how far off the slot is from vertical. Then I remove the screw.

4. Sometimes I will take a countersink and twist it by hand to remove a little bit of metal in the screw’s recess. This is fast and it works well – it usually takes four or five twists to adjust a screw by a quarter-turn. I actually don’t prefer this method, however, even though it is fast. I’d rather adjust the screw (which is disposable), than the hinge (which is expensive).

5. So what I do is wrap the threads of the screw in some masking tape and chuck the tape into my drill press or a cordless drill clamped to my benchtop. I set the drill on fast speed and spin it. Then I take a triangular saw file and touch it to the underside of the screw head. This turns the underbelly of the screw head down a bit. It takes only about 5 seconds of filing to make a difference. Then I unwrap the screw and drive it in.

By the way, I’m not alone in my obsession. Toolmaker Colen Clenton clocks the heads in his beautiful squares. He uses square-drive screws and clocks them to look like diamonds. Nice. There probably should be an encounter group for people like us. I’ll bring the doughnuts.

— Christopher Schwarz

P.S. I know there are still other methods for clocking screws that use epoxy. But I’ve done enough damage today already to your supply of valuable shop time. And if you think I am compulsive, then you should read James Krenov’s masterpiece “A Cabinetmaker’s Notebook.” Krenov was the king of details and opened my eyes to many things important to the craft.

57 thoughts on “How to ‘Time’ or ‘Clock’ Your Screw Heads

  1. peter

    A season craftman and woodworking tutor explained that as a apprentence, he was taught to alighn the slots with the grain direction as a normal practice. Peter (Australia)

  2. gregzall

    One time I asked Krenov about “clocking” screws. ( I was a student when he was teaching in 1992) His response was that he does not clock the screws as perhaps they are not as tight, or my interpretation was that the function of the screw was more important than the way they looked. His response says alot about the way he looks at estetics. And to some perhaps the screws are more beautiful in a random unselfcontious pattern.
    I didn’t write this to be catty or to say “It is wrong to clock screws” (I say do whatever apeals to you.) I just thought it funny that I had to put a little story that was so aplicable to your blog.

    1. russ_p_alexander@yahoo.com

      I agree that if you think it adds to the piece, as I do, then do it. I had no idea that others even did it, or had a name “clocking” for the process. I have done it for years on everything as I think it looks more finished and thought out.

  3. jmail137

    This sounds like something my dad would do. Pretty cool to the me the observer, once i figured out what he was doing, I looked for it everything he did. I think of it more as a fingerprint. Something that reflects the builder… I think it meant he spent a lot of time doing what he did and took some satisfaction.

  4. Phil SpencerPhil Spencer

    I recently viewed a sewing box made by my Great, Great, Great Grandfather in is on display in one of Australia’s premier art galleries. The thing that struck me was the screws and hinges, the hinges were brass and the screws were steel and not clocked. After having discussions with the curator and also a 17th century furniture restorer friend I have been told that this was common practice (steel screws and not clocked that is) for fine furniture of the period, so is clocking the screws a modern thing? I agree it looks better but in the past it was not done a sign of good workmanship they left that for the jointing and finish.

    If I could post pictures I would post some to show the quality of his work.

  5. Paul in Plymouth

    Although I have actually done it on occasion, I usually try to resist the urge to align screw slots. However, this reminds me of an incident along the lines of OCD.

    A few years ago I asked a very meticulous machinist to make some u-shaped brackets for mounting a large leaded-glass shield on a piece of scientific equipment. I gave him a rough sketch with a lot of latitude, and soon received four beautifully machined aluminum brackets that looked like large extra-wide tuning forks.

    Taking the hint, I tapped on them, and they all rang out. Pretty soon I was glued to my watch counting very infrequent beats – they were all well within 1 Hz of each other in frequency. He had machined them so precisely, they all rang at exactly the same pitch. Knowing this machinist, I wasn’t too surprised.

    However, he had his laugh the next day, and I was blown away, when I brought in a real tuning fork and found that all my brackets rang at precisely the same note as the tuning fork – the standard A above middle-C, 440 Hz.

    I’d like to think that whoever installed these brackets on the instrument also thought to clock the screws. I have to confess, though, I never thought to check.

  6. jsparrow

    BoltDepot.com has a very large selection of fasteners including slotted wood screws with several head forms in brass, ss steel, zinc plated steel and silicon bronze. I placed orders with them many times for steel and brass screws and bolts in numerous sizes. Great company.

  7. pathdoc60

    Call me an AR or OCD 69 year old, but I have done clocking all my life (yes, even with switch plates). Why? Because my perfectionist, machinist and beloved and departed Dad taught me this way. Given the superb quality of everything he built including my childhood home, a handmade 48 inch machinist/wood lathe that I still have and use, and a portrait camera ( just to name a few items) I figured that was the best way to install screws. Until now, I never knew the technique’s name, but now thanks to Chris I do. I have learned the filing technique from this blog to make it easier, but with careful recollection, I remember seeing my Dad do that filing on screws as Chris has shown, but until now I did not why he did it.
    Thanks, Chris.
    Clocking out now, I have to go dot a few “i’s” , wash my shoelaces and clean the inside of my car’s exhaust pipe.
    Mike O’Brien

  8. TNWoodwright

    Guess I have a name for my OCD too! Fact is when I built houses the electrician would clock his screws on the switch and outlet cover plates. Straight up and down. It’s the little things people don’t notice that make a difference in the look of a project.

  9. dstampfli

    This reminds me of an OCD problem I have. All throughout my house the screws on all the electrical outlet and switch plates are aligned straight up and down. This did not happen all at once, but over time – whenever I approach an outlet, if the screw(s) are misaligned, I stick my thumbnail into the screw head and tweak it.

    I’ve been known to do this at work, at other people’s houses. where ever I go.

    It takes no time at all, and I feel better about it. Harmless “problem”? I hope so!

  10. Geoff

    Another source; boltdepot.com

    I’m obviously undereducated and sloppy. Though I’ve been “clocking” my phillips and square drive screws for some time I’ve never heard of a term for it; just thought it looked nice. I’ve never used a “technique” for it either; just drive the screw a little further (quarter turn max for phillips and square drives) to line it up with its neighbor. Is there really a need for all the time consuming techniques of clocking a screw?

    Geoff

  11. Ian Stewart

    Hi, Chris,
    I “clock” screw heads as you describe, although we usually call it “align” here in Australia and I always do it with the slot in line with the stile, rather than perpendicular to it as you have done.
    Cheers,
    Ian.

  12. mancave123

    Why does Chris insist on doing things the hard way? The easy answer to clocking the screws is to try a different screw, the slots are not lined up with the wood threads at the factory, so a different screw may just line up better than the one giving you brain fits.

    1. wood4me

      Having checked out a number of slotted screws in different sizes and metals, it appears the slots on different screws do not necessarily all line up with the start of thread.

      So, drive a screw in, if it aligns, bonus. If it doesn’t, remove it and do as mancave123 suggest, eyeball your selection of screws and pick one where the thread starts a little earlier or later than the one just removed. Works for me.

  13. me_rjs

    My OCD is actually a little bothered by the clocking – I like the more usual stochastic pattern. It’s like tuning a drumkit to a certain key – you’re not supposed to do it, you leave it random. It can interrupt the harmony of the other instruments. Likewise, lining up the screws looks too much like a design feature – an unwanted one. When it’s random, it disappears into the background (to me).

  14. bsrlee

    Most places, you can’t get slot headed steel wood screws. The only places I’ve found have been a few hardware stores that have been closing due to retirement of the owner (often in a pine box). I hear that they are available in Brazil, where just to be contary, you can’t find anything else.

    The majority of online stores only carry brass slotted screws, and some of them now only offer Philips head screws (in brass??)

    So – anyone prepared to list some on-line suppliers?

    1. BarryO

      McMaster-Carr (www.mcmaster.com). Personally, I hate the look of visible Philips head screws on hardware, so I switch them out to slotted, which I think look much better with traditional hardware. Most of the hardware I use is brass so I get brass, but they have steel as well.

      On very hard woods like oak, I have my own form of OCD in that I tap the holes and use threaded machine screws rather than wood screws; no worried about twisting the heads off of wood screws as they are driven in. This means that when you replace the #5 wood screws that came with the hinge, you need to use #5-40 machine screws. McMaster even has those.

  15. Richard Dawson

    This may be more widespread than first thought. I once owned an old Mercedes 300D that needed some work. The mechanic where I took it told me he installed a battery and his boss jumped all over him because the cables weren’t perpendicular to the battery housing. Yes, the boss was German.

    Perhaps Screw-Clockers Anonymous isn’t enough.

    Richard

  16. Swarf

    I have been clocking screw slots for some time. Never thought too much about it. I have never figured out for myself whether the slot looks better in the vertical or horizontal. So I alternate from project to project or sometimes it just looks better one way or the other. I feel so weird exposing myself. I may need help.

  17. cbf123

    I read about (but have not tried) an alternate method of doing this that basically involves tapping the screw down to a constant depth before starting to turn it. Done properly this should result with the head at the same position for each screw. Varying the thickness of the spacer used to set the depth will allow control over the rotational alignment.

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