Thread: Sources of Split Nuts For Handsaws

On Monday,

I am heading over to Monaro Timber to select some wood for a handle or two. After my experience with WoodRiver planes with their Bubinga (spelling ?) handles, I was wondering how that wood would go for saw handles. Anyone here in a position of knowledge?

I also figured the wood might also look good with brass split nuts.

Any good alternatives that are really worth considering?

Thanks,

Craig

Originally Posted by Morbius

Well,

Isaac's saw nuts arrived in the post and they are terrific. Compared to the antique nuts I picked up on eBay, these are much better. Not just because they are new, but they are nowhere near as flimsy as the antiques.

I will keep my fingers crossed that Isaac will make these in other sizes, as these are really, really nice. Having a medallion-sized saw nut that you can engrave would be a nice touch.

Now I just need to get my sorry carcass out to Monaro timber to get some decent wood to make a new handle or two

Craig

Originally Posted by Morbius

On Monday,

I am heading over to Monaro Timber to select some wood for a handle or two. After my experience with WoodRiver planes with their Bubinga (spelling ?) handles, I was wondering how that wood would go for saw handles. Anyone here in a position of knowledge?

I also figured the wood might also look good with brass split nuts.

Any good alternatives that are really worth considering?

Thanks,

Craig

I haven't yet worked with it, but I did buy some to try out. Wenzloff uses a lot of it for their saws, and I have one of his dovetail saws with it. It looks great, and I would not hesitate to use it.

These are made for a 7/8 stock with 7/16 heads. The third photo shows my screw (left) next to a Lie Nielsen screw installed in my Lie Nielsen dovetail saw. I have brass only now, working on stainless to complement my folded backs.

Lie Nielsen Type Backsaw screw dimensions.JPGDSCN0063.jpgDSCN0068.jpg

Very nice backs, Rob. I think you could safely ease off the closure a bit, though. I find a firm grip on the saw plate to be more desirable than a really tight grip - makes it easier to adjust in case of any buckling caused by slightly uneven pressure.

I'm also wondering why you don't use a square shoulder or some other in-built anti-twist method on your saw bolts? I know people are using star washers, but I don't think these are really appropriate to use with wood. My observation is that if you live somewhere where there are deep moisture cycles, over time, all handle bolts loosen significantly due to compression of the wood past its elastic point. If the shoulder-less bolts aren't constantly twitched up, and the threads gum up a bit, as they like to do, I fear someone down the track is going to be struggling to re-tighten them. Maybe I'm just an excessive worrier??

Cheers,

That's a HUGE slot, and you buggered the wood when you tightened it! But it's nice to have another source.

If anyone is looking for cheap screws for later saws....



31YZuyvt+WL.jpg


Great Neck Hand Saw Replacement Screws (10 Pack) - Amazon.com

Originally Posted by IanW

Very nice backs, Rob. I think you could safely ease off the closure a bit, though. I find a firm grip on the saw plate to be more desirable than a really tight grip - makes it easier to adjust in case of any buckling caused by slightly uneven pressure.

I'm also wondering why you don't use a square shoulder or some other in-built anti-twist method on your saw bolts? I know people are using star washers, but I don't think these are really appropriate to use with wood. My observation is that if you live somewhere where there are deep moisture cycles, over time, all handle bolts loosen significantly due to compression of the wood past its elastic point. If the shoulder-less bolts aren't constantly twitched up, and the threads gum up a bit, as they like to do, I fear someone down the track is going to be struggling to re-tighten them. Maybe I'm just an excessive worrier??

Cheers,

Hi Ian,
I thought about putting a square shoulder on too. With these screws if the hole in the plate is 3/16" or so there is usually enough friction between the relatively large screw shank and the plate to hold the screw in place, the larger diameter shank also helps lock the plate in place so the screws don't need to exert as much clamping force. If the holes are too large however it can be hard to get them tightly set.
As to the saw backs I agree on the closure. I set these up pretty tight so that they hold a thin plate very firmly. It makes a bit more work in initial setting of the back but once the plate is properly tensioned I think that the tightness of the back helps hold the thin plate true, especially with the relatively deep and long plates I am going to use.
Thanks,
Rob

Originally Posted by Morbius

On Monday,

I am heading over to Monaro Timber to select some wood for a handle or two. After my experience with WoodRiver planes with their Bubinga (spelling ?) handles, I was wondering how that wood would go for saw handles. Anyone here in a position of knowledge?

I also figured the wood might also look good with brass split nuts.

Any good alternatives that are really worth considering?

Thanks,

Craig

Craig,
haven't used Bubinga on a saw, but I did use it on a plane infill, tight curly grain...very strong.
Beautiful with brass & steel.
I would use it on a saw handle without hesitation.
I have some you could use. I was given it a few years ago....have you got any yet?
Regards,
Peter

Originally Posted by lightwood

Craig,
haven't used Bubinga on a saw, but I did use it on a plane infill, tight curly grain...very strong.
Beautiful with brass & steel.
I would use it on a saw handle without hesitation.
I have some you could use. I was given it a few years ago....have you got any yet?
Regards,
Peter

I haven't picked up the wood yet! I finally finished off my saw vice to use for learning to sharpen, so now I have everything just about ready to go through the whole process of restoring saw. I have been leaning towards she-oak recently as I've seen so many great pictures of saws using that recently. Damn this range of choices!!!

Craig

Originally Posted by IanW

I'm also wondering why you don't use a square shoulder or some other in-built anti-twist method on your saw bolts? I know people are using star washers, but I don't think these are really appropriate to use with wood. My observation is that if you live somewhere where there are deep moisture cycles, over time, all handle bolts loosen significantly due to compression of the wood past its elastic point. If the shoulder-less bolts aren't constantly twitched up, and the threads gum up a bit, as they like to do, I fear someone down the track is going to be struggling to re-tighten them. Maybe I'm just an excessive worrier??

Cheers,

Hi Ian,

The Lie Nielsen screws don't have a square shank, and they work just fine. Most of the screws used on 19th century British saws, didn't have any locking mechanism and they have survived for up to 200 years. So I can be fairly confident in saying that you don't need the square shank. But then I have to add, I think it's an improvement that's well worth the little extra effort.

As a matter of interest, the brass founders who made a lot of the cast saw screws were companies like Priest and Co, who actually trademarked the Warranted Superior label screw.. Cheeky buggers...


Warranted Superior
Priest & Co. Pea Croft brass works, 60 Solly street.

Ray

Originally Posted by RayG

Hi Ian,

The Lie Nielsen screws don't have a square shank, and they work just fine. Most of the screws used on 19th century British saws, didn't have any locking mechanism and they have survived for up to 200 years. So I can be fairly confident in saying that you don't need the square shank. But then I have to add, I think it's an improvement that's well worth the little extra effort.

As a matter of interest, the brass founders who made a lot of the cast saw screws were companies like Priest and Co, who actually trademarked the Warranted Superior label screw.. Cheeky buggers...


Warranted Superior
Priest & Co. Pea Croft brass works, 60 Solly street.

Ray

Hang on a bit, Ray, the shank on that funny medallion bolt looks distinctly like it's square, to me. Maybe it's just artist's licence?

I agree you can tighten a new screw without much effort, I'm thinking about down the track. As you say, you can live without 'em, but adding the square shoulder isn't a lot of effort, and it is a help. In fact, making a bolt takes me just a couple of minutes, the nuts take more time because there are more steps involved, the way I've been making them....

Cheers,

Another reason I opted for a thick shank vs. the squared section is that with these screws the thickness of the section of wood through which the locking square seats is quite thin. Given the modern predilection for more decorative woods that can be more susceptible to breakage with the grain I thought it wise to go with the thick shank. One of the woods available in abundance here is mesquite and there is decent demand for quality pieces. Some of the best pieces I have were originally consigned to use as firewood. Mesquite is quite hard but will crack with the grain, especially thin sections. I am doing experiments to stabilize it using vacuum infusion - I'll post information when I have enough to make a story.

All,

With the thankful departure of the holiday season I have some time to get back to you with my reasons for designing my saw screws as I have.

The first figure below illustrates an analysis of the forces on the saw screws that occur during sawing. The primary forces are parallel to the long axis of the plate/back assembly. However, due to the arc described by the fore and aft motion of the humerus, there is also a rocking component that induces forces perpendicular to the long axis of the back.

Fig 1 saw screw discussion.JPG
Measurements of a specimen Lie Nielsen dovetail saw show the following dimensional features of the saw screws and the holes in the saw plate.

Fig 2 LN screw and saw plate relationship.JPG

If we examine the case where the screws may be loose due to the lack of square shoulders, which as has been observed above they do indeed lack, we have a minimum range of motion of approximately 0.0055" at each screw and the distance between the screws is 0.625" giving us a range of motion of the handle relative to the plate of approximately 0.011"/0.625" = 0.0176"/inch at each screw hole. The distance between the center of rotation, assumed to be midway between the screws and the co-linear point on the extreme back of the handle, corresponding to the approximate position of the top of my ring finger, is 4.35". Thus we have the potential, purely from screw looseness, for the tote to move up and down through approximately 0.0176" X 4.35" = 0.076" or about 5/64". This does not seem like a large problem but think of the implications: All of the clamping force holding the plate must be exerted by the cheeks of the handle onto the plate and or the mortise for the spine. Over time the excess stress caused by poor screw to screw hole fitting will likely cause the handle itself to wear. Thus if you have under-size screws you really do need to keep them tight to avoid this rocking motion - which argues for a square shank.

Now let us consider the case of the square shank more closely. Figure 3 below illustrates the relation of the parts and the grain of the wood.

Fig 3 Square shank schematic.JPG

In Figure 4 is shown the situation that may occur when a square shank screw is tightened.

Fig 4 Square shank forces analysis.JPG
Clearly, if the square shank is fitted less than perfectly there will be a tendency of the screw shanks to cause splits in the handle.

This problem would be compounded by a sloppy screw shank to saw plate fit as exists in the case of the LN saw necessitating high screw nut torque to keep the handle stably fixed to the saw plate/ back assembly.

The wood used introduces another source of trouble. In the old days the majority of saws were stocked with beech, maple, apple or perhaps pear, all of which tend to resist splitting. The modern tendency to use wood of higher aesthetic appeal but in some cases lower resistance to splitting thus further increases the chances of system failure. The wood is already thin and cutting a mortice will thin it further.

This is why I have elected to leave off the square shank on the dovetail size screws. The relatively thicker shanks of my screws fit the holes in the saw plate more closely and thus limit handle slop without the need for high tightening torque.

Just my opinion of course and I am trying to do this the best way possible. There are other options, such as tapering the hole with a matching tapered shank, but how to avoid the splitting forces? A drop of BLO under the screw head? Lock washers? Ferrules/bushings? Like everybody however I'm on a budget.

Just throwing my $0.02 in here, with a few random thoughts on saw bolts.

I use serrted tooth lock washers on my bolts and saws. When you use these, you need to be aware that they need to be installed in the correct orientation. Because they are stamped from a sheet, the teeth on one side are markedly sharper than on the other. The sharp side should be placed against the underside of the bolt head, as it will better bite into the metal.

When I install them in this manner, they can be tightened to a great degree. I have installed hundreds of them, and have never had one slip. I have, however, bent the tips of split nut drivers trying to overtorque them.

I don't know if it is as good as using a square shank in the long (very long) run, and will be long gone before the final verdict is in. But if I didn't believe that they work well, I would not use them.


Regarding snug fits between the blade and the bolts, that is something I try to avoid. It may help to keep things tight, but will stress the handle as it shrinks and expands in response to changes in its moisture content. It may or may not harm the wood, but I have stripped the threads on many an old saw bolt that was jammed tight against the edge of its hole in the blade when the handle shrank.

I owuld much rather rely on friction to hold everything in place. It doesn't take much torque on the nuts to provide enough of it, and it is a simple matter to tighten the nuts up when needed. In my experience, most saws will need to be tightened up less frequently as the wood settles in.


This is a lot like picking nits, of course. In the moment, it seems extremely important, but from a distance it is a bit less so. Judging from the vast numbers of saws that have survived more than a hundred years of untold indignities, I'd guess that any of the saws made today have a good chance of outlasting any of us.