Gramercy Holdfast Help

[Matthew N. Masail]

I bought a set of these a while back, but found they didn't hold very well, so I fixed them up as per this video https://www.youtube.com/watch?v=S7lnfW4iT6o
Still, they "stick" but they don't hold. even if I hit them in with quite a bit of force I can still swing the board around with ease, I have resorted to using clamps again.


Now, based on everything I've read and on that video, I think hold fasts are supposed to hold much stronger than what I'm getting, right?


The round do holes in my bench are 2 1\2 inches deep, others are 1 1\4 . all holes are 3\4inch in size. I'm wondering maybe I need deeper holes? different size? I'd like to make holes on the side of the bench too and really enjoy the holdfasts, but not until they can hold stronger than a 5 year old kid :confused:

a friend of mine has a set too and they don't hold any better than mine so I don't think I got duds.

[Matthew Hills]

Is the problem that the hold-fasts are not staying in the holes, or that the workpiece is pivoting? Is it able to clamp down tight on a small chunk of wood, or is even that weaker than desired? does it never hold tight, or is it loosening as you are trying to work?

What is your bench made from, and what surface treatment does it have?

My bench is ~3" thick (unfinished doug fir) and the hold fasts stick well when whacked in with my wooden mallet. Thicker tops reportedly have more problems holding the hold-fast, with the general suggestion being to counterbore from underneath (rather than the hold-fast dimpling shown by Richard in the video). I'd expect that your 2.5" holes should be pretty much ideal. I don't have experience with 1.25" thick top.

How tight are the holes around the hold-fasts when first dropped in? (i.e., is it hard to insert the hold-fast, do they drop in, or do they have a lot of space around them?)

If the issue is the workpiece moving despite having the hold fast staying fast… how flat is your bench (and workpiece), and what finish do you have on it?

PS--in frank klausz's recent video on joinery, he is setting up his post-retirement shop and uses some TFWW hold-fasts. He did have some trouble when chopping on a table leg. In that case, his workpiece was pretty thick, so the hold-fast was pretty high (workpiece thickness + scrap), he was using a single hold-fast, and he was starting to get some vibration in the workpiece when he was chopping. The hold-fast loosened up with the vibration. He switched to a clamp at that point. He was using the hold-fast later without any problems, when chopping out drawer dovetails.

Matt

[jason thigpen]

I had the same problem. The holdfasts would get nice and tight, but the wood still was able to move some. Glueing leather pads on each of the holdfasts fixed that. Now they are rock solid with just the lightest tap to secure them.

[Matthew N. Masail]

Thanks Matthew, lol.

the workbench is flat, top surface is poplar, unfinished, but most of the doghole is beech.
the holdfast have just little room in the hole, not tight but not at all loose.

the issue is as you said, the holdfast stays put very well, but applies very little pressure to the work piece no matter how hard I tap it in.

[Matthew N. Masail]

I had the same problem. The holdfasts would get nice and tight, but the wood still was able to move some. Glueing leather pads on each of the holdfasts fixed that. Now they are rock solid with just the lightest tap to secure them.

I tried that. now 1 has a leather pad and one is bare so I could see the difference, but they are both the same.

[Matthew N. Masail]

Hi Jim, I mentioned in the first post the I had already done that. maybe there is something wrong with my holes. the first 1" is plywood, maybe thats the isuue. I'm going to experiment and
see how it goes.

[Jim Matthews]

My bad, I wasn't paying attention and that's a peeve of mine (when other people do it).

Did you raise enough metal around the pin strikes to feel a roughened surface?
If so, I think you may need to inlay a hardwood strip in your existing bench.

The plywood may have fractured in use, enlarging the holes.

Have you any detail pictures of the problem?
It's of interest as workholding is an elemental concern for benches.

[Jim Koepke]

A single holdfast will not prevent a piece from pivoting.

If the holdfast is lightly tapped down with a mallet, pulling straight up on it should not cause it to release.

A holdfast needs to be a little loose in the dog hole in order to have room to become jammed. Your comment, "the holdfast have just little room in the hole, not tight but not at all loose," leads me to believe your holdfasts may need to have a larger hole than a standard dog hole to get a grip.

I use my holdfasts on a piece of 2X construction lumber that is the top of one of my sawing benches.

My suggestion would be to also try some scrap lumber with different sized holes to see if it is the fit in your bench dog holes that might be the problem. The solution would be to bore some holes only for use with the holdfasts.

My holdfasts were made by Harry Strasil and work fine. My recollection is the shafts are made of 5/8" rod.

My biggest problem seems to be my bench's material can split a bit if they holdfast is driven too enthusiastically with a mallet.

jtk

[Jessica Pierce-LaRose]

I tried that. now 1 has a leather pad and one is bare so I could see the difference, but they are both the same.

From this, it sounds like you're only using one holdfast at a time to secure something ? If that's the case, i can often rotate things under a holdfast when using it in this fashion, because it's held by a single point, depending the board and how far from the holdfast the working end is. For something like chiseling dovetails (where all the force is focused downwards) it's not much of an issue, but depending on how you're applying force, it may be a problem. Often times, just butting the free end of the board against the shaft of the holdfast is enough, but usually I would either use two holdfasts, or a holdfast and a bench dog, depending on what I'm doing, and how the force is being applied.

When working with softer woods, I often use a piece of scrap underneath to keep the holdfast from marring the workpiece, this seems to also help secure things a little better, as well.

[Matthew N. Masail]

Jim M, I know what you mean, I do it too sometimes out a laziness and then always feel like I was goof. If the experimenting doesn't fix it, than I'll take a video of the issue.




Jim K, "A single holdfast will not prevent a piece from pivoting" thats good the know! but still it should be somewhat firm, I can move it by breathing on it the right angle!
I am going to experiment with some construction lumber and see how it goes, I've had a feeling since Matthew H asked that my holes are really a little small. the metal raised from the hammering made this worse, so I filed off the peaks and it's still rough but the tilt and grab are a little better. also I think the plywood layer gives in more than the wood underneath it making the tilt uneven. I'm planing on a new bench so this is definitely something I'd like to solve first!




Thank for all the help ! will post results when I get it right.

[Jim Koepke]

it should be somewhat firm, I can move it by breathing on it the right angle!

Usually when I jam a holdfast into a dog hole onto a piece the holdfast will not easily pull out.

So far all that has been said makes me think the dog holes are too close to the holdfast shaft's size to work properly.


I'm planing on a new bench so this is definitely something I'd like to solve first!

This is something a few auger bits, a brace and a little time should help you to find the best size hole for you holdfasts. My plan is to have separate holes for the holdfasts and bench dogs. The dog holes will run close to the edge and the holdfast holes will be set in from the edge a few inches.

jtk

[Matthew N. Masail]

Usually when I jam a holdfast into a dog hole onto a piece the holdfast will not easily pull out.

So far all that has been said makes me think the dog holes are too close to the holdfast shaft's size to work properly.



This is something a few auger bits, a brace and a little time should help you to find the best size hole for you holdfasts. My plan is to have separate holes for the holdfasts and bench dogs. The dog holes will run close to the edge and the holdfast holes will be set in from the edge a few inches.

jtk

Sounds good. it's pretty much the set-up I Imagin, Thank g-d I have a friend who has a brace and auger bits.

[Jim Koepke]

Sounds good. it's pretty much the set-up I Imagin, Thank g-d I have a friend who has a brace and auger bits.

I would be lost without my own brace and bits.

So much so is my feeling about this that there are now a few more braces in my shop than I will ever use.

Sadly, it looks like shipping to Israel is more than any or all of the braces are worth.

jtk

[Matthew N. Masail]

I would be lost without my own brace and bits.

So much so is my feeling about this that there are now a few more braces in my shop than I will ever use.

Sadly, it looks like shipping to Israel is more than any or all of the braces are worth.

jtk

Yeah but I'm blessed with relatives in the US, so It should be ok when the time come! my friend who has a set in 1\16 increments just bit the bullet.. also a way to go.

[Jim Koepke]

my friend who has a set in 1\16 increments just bit the bullet.. also a way to go.

A bullet I can't seem to stop biting. It is hard for me to resist bringing home decent bits if they are priced right.

jtk

[John Powers]

Mine work fine. After I glued leather on and really mauled them with my angle grinder. To be fair I think my table top is too thick but roughening them with sandpaper won't do the job. I set them with a mighty wack.

[Mike Brady]

These holdfasts seem to be a hit-or-miss proposition. I never got mine to work, even with leather pads and roughing with sandpaper, and sold them to a friend. He likes them. My bench is 3-1/2" ash. Cast ones from Lie-Nielsen worked better.

[Jim Koepke]

These holdfasts seem to be a hit-or-miss proposition. I never got mine to work, even with leather pads and roughing with sandpaper, and sold them to a friend. He likes them. My bench is 3-1/2" ash. Cast ones from Lie-Nielsen worked better.

Mike,

Is there any chance you measured the shaft size of both sets?

If so was there a difference?

jtk

[george wilson]

You guys are doing something wrong. We used holdfasts all the time in Historic Trades,and I never used but one at a time,nor did the cabinet makers next door. We might have had better holdfasts. Mine is quite heavy duty. I need to take a picture of it. From what I've seen,mine is considerably more stout than even the ones Peter Ross makes. It's corner,between the shaft and the arm,is quite solidly filled in. No way can it ever tend to bend under the force of driving it in tightly to hold the work. Yes,it needs to be used with a loose fitting hole,in a good,hard maple or other similarly hardwood top. My bench tops have always been about 4" thick. You need the bench top to be good hard wood in order for the holdfast to bind well.

Oh,yes,you could intentionally force the wood to go sideways. But,for any planing operations we ever did,the hold fasts were quite secure.

[ian maybury]

It's possibly worth thinking specifically about how holdfasts work. This is just my take, but the key point is likely that it's the working forces acting with the geometry of the holdfast's straight shank and the hole that create the grip, and much less so friction within the hole/between the steel and the wood. I'd be wary of stuff like punch popping the shank, as it seems likely to risk wear to dogholes and to possibly not add that much that would be consistent - although degreasing (getting traces of oil in dogholes has the potential to cause big problems) and sanding as Grammercy suggest can't do any harm. Wear to/enlargement of the dog hole caused that way could sometimes prove helpful (see below), but it might not be even in all directions.

Take a look at this quickie sketch:

293076
My guess is that the relationship between the shank diameter and the dog hole diameter (the clearance) and the thickness of the top is the key - these together determine the angle marked 'A'. When the holdfast is hammered in and bears on the bench top/holds down the work the result is the reaction force marked 'F'. (it's at right angles to the clamped surface) This (because of the layout of the holdfast - the arm projects out to the side) immediately causes the twisting moment/torque marked R about the point marked +. (located on the shank and somewhere between the bench top and bottom surfaces)

This torque is resisted by contact with the top and bottom edges of the dog hole - but not before the holdfast has tilted out of vertical (relative to the bench top) by this angle 'A'. It's tempting to think that it's friction at these points that retains the holdfast (and no doubt it helps), but there's likely something a bit subtler going on.

Force 'F' is basically vertical (relative to the bench top), which means that it acts to try to lift the tilted holdfast vertically out of the hole.

This isn't possible - because the shank of the holdfast is held tilted at angle 'A', and in this crosswise orientation it can't fit up through the dog hole. So the holdfast is held locked down - the projecting straight section of the inclined shank in effect 'hooks' under the bench top. Whacking the back of the holdfast to release it stands it back up into the vertical (the foot must move horizontally by a small amount to achieve this) - freeing the shank to slide in the dog hole. So it releases.

My guess is that the key to getting holdfasts to grip is to ensure that angle 'A' is correct. i.e. is enough to permit this hooking effect to work. If it's too small a little flexing of the shank may permit it to slide a bit and release completely. The shank needs to be long enough to project past the bottom of the bench too.

It'd be interesting to test how effectively a holdfast works for differing values of the angle 'A'. There's various ways it can be adjusted. Too tight a dog hole or too thick a bench top may both reduce it below the required minimum. The common fix of counterboring from below to reduce the effective thickness of the bench top will increase it for a given dog hole and shank diameter/clearance. It should increase the vertical holding capacity (max 'clampable' workpiece thickness) too.

It wouldn't be too hard to make up a test block and to trial the various hole options before modifying a bench top.

Has anybody ever tried enlarging the dog hole diameter by a hair in the situation where holdfasts are not gripping well? One downside to fixing a problem by increasing the hole diameter this way (as well as not gaining the extra capacity - and even if it restores grip) might be that it could interfere with the function of some of the other 3/4in dia dog-hole mounting products about. (e.g. the various Veritas locking dogs) it'd depend on what tolerance/how large a hole they can handle.

Another thought on the causes of the problem (in addition to recently thicker bench tops). Lots are boring dog holes now using routers and spiral cutting bits. Wonder is it possible that these (while delivering a nice clean hole) may tend for a nominal 3/4in size to deliver a smaller dog hole diameter than your average drill bit which tends run a bit off centre/to bore a shade oversize?

ian

[george wilson]

In the 60's I used a blue Marples holdfast that Woodcraft Supply sold. It had the tightening screw on the arm,and was made of cast iron. I had a problem with it slipping in the hole it went into. This was cured by filing a bunch of grooves across the back side of the shank. That way,the shank could better bite into the workbench. I never used the cast iron collar that came with it as that would have limited me to 1 location only for the holdfast.

I might suggest that you file teeth across the back of your holdfast with a thread restoring file,where it touches the wood. This type file isn't very expensive,and can be had at any auto store,or Walmart. You might also find it useful for "Knurling" knobs,though a real checkering file from Brownell's Gunsmithing would be a lot better. I haven't actually used a thread restoring file for this myself,but it is a thought.

I haven't had to do this with my hand forged holdfast,but you might find it useful.

[Matthew N. Masail]

Ok. I have some work to do... :) my first goal to find the right thickness and hole size. but first... the Ivory paint came today.... :rolleyes:

[Michael Hewett]

Whatever happened with this? I have the same problem and I wonder what the potential solution is? did you every determine the solution to your satisfaction?

[Joe A Faulkner]

Michael, you say you have the same issue? How thick is your bench top? Have you glue leather pads to the ends of your hold fasts? I glued a soft suede leather to mind, and roughed up the shank with some 100 grit paper. They are working great in a 3 1/4" thick maple top.

[Gary Cunningham]

I use mine in pairs. 3 inch southern yellow pine bunch top. I like to plane across the bench top, using a thin board held on the ends by two hf's. They hold just fine by placing the thin board against the hf's.

when using one hf's they can work loose.

[Mike Brady]

I had no luck with the Grammercy holdfasts in my bench. A friend ended up with them and they work fine for him. For the record, my bench is 3-1/4" ash. I had sanded the shafts and put leather pads on them. No dice. Lie-Nielsen cast holdfasts replaced those and work great. I feel if you have to hit holdfasts very hard to set them you are just deforming the dog holes.

[Frederick Skelly]

I have a pair and they work very well. I sanded them "round and round, not up and down" like their web site says. My bench top is also yellow pine (just dimensioned lumber), about 3 1/4" thick.

[Derek Cohen]

Matthew, it's a bit of a mystery to me why your Gramercy holdfasts are not holding fasting. I drilled two more holes for mine just yesterday, and - as with all the other holes - they worked immediately. Indeed, they hold so tightly that they take some effort to release.

Gramercy state that the holdfasts are for a bench from 1 3/4" using 3/4" holes. Feedback is that they do not work well with 4" or more benchtops. My benchtop is Oak and and the holes a nominal 3/4" with brace and bit (don't try to use any other method!). These holes work equally well with the Veritas holdfasts. The only modification I have on my Gramercy holdfasts is to glue leather to the heads to prevent damage to the work piece. It is not for gripping. That is unnecessary. One at a time prevents most movement.

The only held you will get from the above is that they work very well.

I would look at your bench material and the holes. I suppose that some woods/wood composites may be too slick to grip - one of the reasons that Gramercy have suggested sanding the shaft for extra resistance. Together with a hole that is tight, there will be too little side movement (very little is evidently needed) to add to the resistance needed. Try roughing your holes before you try anything else (coarse sandpaper glued to a dowel, or a gentle use of a hacksaw blade).

Regards from Perth

Derek

[Augusto Orosco]

I have no deep knowledge on this matter, but I would hypothesize how perpendicular your holes are makes a difference. I have two holes in my 3.75 thick soft maple bench and the holdfast holds well in one (the straight one) and rather poorly in the other one (which I drilled carelessly at some sort of off 90 angle). Mine are not gramercy but LN.

I don't know if that's the real reason, though; perhaps there are other variables I am not noticing.

Good luck with yours.

[Derek Cohen]

they "stick" but they don't hold. even if I hit them in with quite a bit of force I can still swing the board around with ease, I have resorted to using clamps again.

Matthew, one more thought.

Reflecting on the above, that sounds like the pad of the holdfast is not seating firmly or evenly on the work piece (alternatively, your bench has many high spots). Do you place a waste block on the work piece before tapping down the holdfast (it should not need more than a light tap)? A piece of leather under the pad would do this and also protect the work piece from the steel pad.

Regards from Perth

Derek

[Matt Lau]

Ditto to what Derek said.

Some cork would work well too.

[Mike Brady]

Since the Grammercys are just steel rod, they should be uniform diameter (whatever the ad copy states they are) and smooth. The LN holdfasts are cast ductile iron with a very sand-mold textured surface. I'm guessing that material difference is a key to why they hold so much better. I think leather pads make a big difference in how they hold too.

[Prashun Patel]

I had the same problem with my Grammercy hold fasts. I have two benches: both are about 2 1/4" thick.

I found the problem is my dog holes. My hold fasts require a tight tolerance on the holes.

I redrilled a bunch of holes in my bench with a proper bit and guide and now the holdfasts work better.

I would think eventually the holes get elongated, but for now they're working ok.

[Mike Siemsen]

I probably have 5 pairs of the Gramercy holdfsts and they all work fine in all of my 8 or 10 benches i have. 3/4 inch holes 1 1/2 to 3 inch thick construction lumber , 2 1/2 inch birch and ash and poplar and maple. I did nothing to any of the shafts probably wiped any oily residue off when they arrived. I wonder if you waxed your bench top or the holdfast shafts. Mine hold well enough to lift the bench off the floor which is a better test than seeing if the workpiece pivots.

[Matt Evans]

I'll agree with Mike, had these on lots of benches now and they do work great.

One of a set I got had a small ridge on the bottom of the pad, almost unnoticeable, but still present. That got filed flat in a few passes of a rough metal file, and has performed perfectly since. Before filing, the ridge did cause the pivot, even when tapped down hard and fast.

[ryan carlino]

I'm in the "they work great" camp. I have a hard maple bench, just under 4" thick. 3/4" holes. Slight sanding (round-and-round) when they arrived and you can't remove them after a firm hammer blow. I always use a block of whatever wood is hanging around as a pad, since they could dent softer woods.

I started drilling my holes with a 3/4" plunge router and finished with a longer bit in an electric drill. The holes are very close to 3/4" finished size, but probably not perfectly linear, since 3/4" dowels slide easily in and out in some hole and get stuck in others. That said, the holdfasts work great in all the holes.

[Christopher Charles]

Hello all,

I've had the Gramercy holdfasts for several years now and they've worked great. Until last week. I'd noticed a couple of rust spots so had lightly sanded and wiped down with oil without really thinking about it. Wasn't till a week or two later that I went to use them and no-joy. Took a bit to figure it out. A quick round and round sanding and they're back in business. FWIW, I use them without leather pads and in a 4" hard maple bench with 3/4" augured holes. Keep 'em dry...

Best,
Chris

[george wilson]

A thicker bench top will require larger holes for the hold fast. They need to cock over at an angle to effectively jam in the holes. My work benches have all had close to 4" thick tops. One is maple and the one I have at home is beech. I can't speak for soft wood bench tops.

Don't forget my advice to buy a thread restoring file to quickly cut multiple grooves on your hold fast shanks.

I have never found it necessary to cut grooves in my hold fasts(The blue Marples one worked differently,being tightened with a screw).

By the way,I only EVER strike my hold fasts with a LARGE WOODEN MALLET,not a steel hammer. They mushroom over time and get work hardened and can eventually break if you keep hitting them with a steel hammer. And,they look ugly when beat up.

[Prashun Patel]

Thanks for these tips, george.

[Christopher Charles]

Indeed, thanks for the tips, George. I'm intrigued about the thread restoring file.

[george wilson]

The thread restoring file is a square file about 9/16" square and about 9" long. It has 8 different pitch threads on it. You use it to smooth out the lumps in beat up threads. Not an expensive file. Useful for ornamentation too,on carvings or other work. Can be used as a substitute for knurling on knobs you might want to knurl,but have no lathe.