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Thread: Holdfast Question

  1. #1
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    Holdfast Question

    I used (and enjoyed using) holdfasts in a friend's shop, and now that I'm getting my own workshop set up, I'm in search of a pair. There is a local smith who can produce them, but I've got a couple of questions before I put in the order. I've not been able to ask my friend for a variety of reasons, including his failing health.

    First, shank size. 1/2" or 5/8"? My bench is relatively new and does not yet have dog holes, so that will not play into. Any real difference, or does it just depend on what stock is on hand?

    Second, bench compatibility. My relatively new bench is also relatively crummy. Solid, heavy, and flat, but the top is 3/4" ply covered with 3/4" MDF. When I can, I plan to construct a more traditional top, but so far it's been a suitable first bench. I'm wondering if a) the holdfast will even grab in that material and b) if so, will the MDF just blow out immediately? (Which might give me the excuse I need to get going on a better bench.)

    Thanks for the help. I hope this hasn't been covered at length - I searched several threads but couldn't find satisfying info.

  2. #2
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    I think my hold fasts have 5/8" shanks.

    As to blow out, if they are whacked hard enough when you set them, they can break sold beech. DAMHIKT

    jtk
    "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty."
    - Sir Winston Churchill (1874-1965)

  3. #3
    Quote Originally Posted by Jim Koepke View Post
    I think my hold fasts have 5/8" shanks.

    As to blow out, if they are whacked hard enough when you set them, they can break sold beech. DAMHIKT

    jtk
    They certainly can. That's the biggest complaint I have about my Sjoberg bench. 1" dog holes. ERROR ERROR ERROR. Not only can you not find many accessories in 1", holdfasts bust them so much easier because of the added leverage IMHO.

  4. #4
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    My current, craptastic bench has an MDF core with a layer of Souther Yellow Pine on top. Holdfasts do work ok on it, but I don't think they grip as well as they might on a solid wood top.

    For your bench they will probably do a decent, but not ideal job grabbing. I haven't had problems with "blowout" of the MDF, but more of misshaping over repeated use.
    Last edited by Chris Griggs; 09-16-2010 at 3:49 PM.

  5. #5
    I used 3/4" round holes in all of my benches as there are a wide array of accessories being made commerically for that size these days.

    As far as holdfasts go, the ones Joel over at Tools For Woodworking sells are excellent, and not at all expensive, I think a set of them runs < $40 and they arent made of fragile cast iron.

    On your depth of benchtop question, I have had issues with dog holes in tops that were 1 1/2" thick (specifically in fir/pine) deforming under use. I found that simply adding another 1 1/2" thick strip of wood under the dog holes (allowing for 3" deep holes) significantly reduced this deforming and the grip was much better.

  6. Quote Originally Posted by Jeremy Dorn View Post
    As far as holdfasts go, the ones Joel over at Tools For Woodworking sells are excellent, and not at all expensive, I think a set of them runs < $40 and they arent made of fragile cast iron.
    Another vote for the Gramercy Holdfasts.

    http://www.toolsforworkingwood.com/i...MS-HOLDFAST.XX

    I have a pair and love them. I used them at Roy's Woodwright School, and picked up a pair.

    They work in 1 3/4" wood, although I am building my bench top to be a bit thicker. I made a sawbench out of some douglas fir 2x8, and drilled a 3/4" hole in the top, and it works fine just like that.

    Not affiliated, just a happy customer.

    badger
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    Last edited by Brander Roullett; 09-16-2010 at 4:34 PM. Reason: adding pictures

  7. #7
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    The Gramercy ones are 11/16", to be used with a 3/4" hole. Since you will be drilling holes to match the holdfasts after they are made, they could be any size as long as they are thick enough to withstand the use. I would recommend having them made a size just slightly under a common drill diameter. Especially in a thinner workbench top, the closer the diameter of the hole is to the diameter of the holdfast, the more vertical the holdfast will sit in the hole while in the "holding" phase. I am not certain about the physics but I think this would require less force to wedge the holdfast; therefore less force on the sidewalls of the hole, therefore less likely to blow out. Tools for Working Wood says theirs are intended for workbench tops at least 1-3/4" thick. Depending on how many layers of ply and MDF you have, you may need to add some thickness underneath where you drill the holes, if possible.

  8. #8
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    Another option

    The holdfasts from Lee Valley. Although expensive, you don't need to pound them for them to grip. They have a very rough surface to grab and plenty of power to hold. They work in 3/4" holes. My set works fine.

    I also have some from Jr. Strasil that work well, and I have gotten them to hold in the flat side of a 2x4. I prefer this set for speed and really enjoy using them.

    If you are drilling holes, don't forget about bench dogs. They are also quite handy.

    Eric

  9. #9
    I have two of the Gramercy holdfasts, and they worked fine on my old plywood/MDF benchtop (1 1/2" total thickness) with 3/4" holes. The MDF edges will get worn after a while.

    Now I'm using them on my 3 1/2" thick SYP Roubo bench and my 1 1/2" thick poplar portable bench, again hold fine.

    They beat the heck out of the cast one I bought at a woodworking store. They're made of steel "wire" (of a gauge suitable for holding up the Golden Gate bridge), so have some very slight spring to them without risk of cracking like a cast one. The cast one is too stiff.
    Steve, mostly hand tools. Click on my name above and click on "Visit Homepage" to see my woodworking blog.

  10. #10
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    Not the answer you're looking for but, for a more controlled holddown (although slower to set and release):
    "A hen is only an egg's way of making another egg".


    – Samuel Butler

  11. #11
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    Thanks, folks for all the feedback so far. I appreciate the recommendations for Grammercy, etc., but I'm definitely going local on this.

    So, if I figure 3/4" dog holes, 1/16" smaller than that on the shank is about right?

  12. #12
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    No, No, Ignore all these suggestions for holdfast sources. Stick with the local smitty! I can't really offer you much help on the size, other than offer an opinion that since you have no holes drilled yet you could probably experiment on scrap to match the hole to the holdfast. I've found a couple of holes, strategically drilled on the benchtop, are all that are really needed for holdfasts (but that's a personal observation, and may not suit your way of working).

    Edit: ahh, you posted your response while I was typing. I'm relieved!
    Last edited by Mark Maleski; 09-16-2010 at 10:04 PM. Reason: Additional data became available.
    Mark Maleski

  13. #13
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    I use 3/4" shank holdfasts, but I drilled 13/16" holes in my bench top and apron. FWIW
    Jr.
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  14. #14
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    I have a set of Harry's holdfasts, they work great. Whatever dimensions he uses will work well.

    "I use 3/4" shank holdfasts, but I drilled 13/16" holes in my bench top and apron. FWIW"

    Quote Originally Posted by Karl Wicklund View Post
    Thanks, folks for all the feedback so far. I appreciate the recommendations for Grammercy, etc., but I'm definitely going local on this.

    So, if I figure 3/4" dog holes, 1/16" smaller than that on the shank is about right?
    Paul

  15. #15
    Quote Originally Posted by Karl Wicklund View Post
    I used (and enjoyed using) holdfasts in a friend's shop, and now that I'm getting my own workshop set up, I'm in search of a pair. There is a local smith who can produce them, but I've got a couple of questions before I put in the order. I've not been able to ask my friend for a variety of reasons, including his failing health.

    First, shank size. 1/2" or 5/8"? My bench is relatively new and does not yet have dog holes, so that will not play into. Any real difference, or does it just depend on what stock is on hand?

    Second, bench compatibility. My relatively new bench is also relatively crummy. Solid, heavy, and flat, but the top is 3/4" ply covered with 3/4" MDF. When I can, I plan to construct a more traditional top, but so far it's been a suitable first bench. I'm wondering if a) the holdfast will even grab in that material and b) if so, will the MDF just blow out immediately? (Which might give me the excuse I need to get going on a better bench.)

    Thanks for the help. I hope this hasn't been covered at length - I searched several threads but couldn't find satisfying info.
    I also like the gramercy variety. Why not get your guy to make that type instead of forging something.

    I'm in the category of someone who bought those original cast pieces of crap that sell at all of the "let's import junk now" woodworking mail order places carry. I broke them. I didn't feel like I was abusing them, I just broke them. One of them had apparently had enough and broke off to reveal very large sandy grains of metal when I was barely tapping it.

    Anyway, round spring steel is cheap - like $12-$15 from mcmaster carr to get a piece big enough to easily make two holdfasts. I really like that no matter how hard I beat it, I have no worries.

    FTR, for those of you who use wood benches with thin hardwood tops (I have a beech bench with 1 inch or 1.25 inches of top thickness), the gramercy holddowns work fine. Actually, they work extremely well.

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