I have a project that I want to thread the wood instead of using inserts. I tried metal taps but couldn't get nice threads in wood without imperfections. I just want to make the parts with the cnc and avoid buying and installing 200 inserts. I looked around and found taps made for wood and finally ordered a set from Infinity tool. I was surprised how they just came in plastic sleeves and looking at them there is no country of origin stamped on them. They were expensive but look like Chinese taps made from Chinesium so I have my doubts about longevity. Tried them all and the results are excellent with perfect threads and no tearouts like the metal taps. The threads seem very strong in ash and are very quick to make just using a drill. Thinking about trying wood wax on the bits to make them last longer like my Beall taps. Hardwood and softwood require different pilot holes but I didn't have any softwood to try. Thought I would start a thread where we can share experience trying to use wood threads instead of inserts to see what works. Here's what they look like
(https://forestryforum.com/gallery/albums/userpics/34694/20231216_161735.jpg?easyrotate_cache=1702769005)
(https://forestryforum.com/gallery/albums/userpics/34694/20231216_161757.jpg?easyrotate_cache=1702769003)
(https://forestryforum.com/gallery/albums/userpics/34694/20231216_161837.jpg?easyrotate_cache=1702768999)
These are the Beall taps I have had success with using threaded wood bolts
(https://forestryforum.com/gallery/albums/userpics/34694/20231216_162113.jpg?easyrotate_cache=1702768999)
I guess the knobs with threaded studs will require a good coat of protectant to keep the steel threads from rusting with moisture in the wood.
Well I have never thought of machine threads in wood having much strength. I am wondering what your application is for all those holes? Moisture changes and all that wreak havoc with machine threads in wood.
I have one regular product where I tap a machine thread into wood for an 8-32 thread, but this screw is used more as a locking pin than it is a screw and the thread is just to hold the pin in it's place. There is no pull force on the screw at all. It is finger threaded in and out and does not need to be tight.
SO what do you have going on there?
could reinforce with thin viscosity epoxy, and then retap to stabilize and strengthen.
I'm just making a bunch of adjustable racks and some holding fixtures first to see how they work. Mostly 3/4 thick indoors use. I tried stripping out the 3/8 thread with a wrench and washer under the bolt head but it didn't cranking on it with about a 6 inch long wrench. The 3/8 and up seem very strong. The 1/4 and 5/16 will take all the torque I can put on them with a screwdriver without stripping in 3/4 ash. I'm going to try some inch thick maple next. Had to order some sharp brad point bits first because mine have all seen 30 years of use and I can't figure out how to resharpen them plus ordered a set in 1/64 increments to see how hole size affects thread strength because their recommended sizes don't seem prefect. The bolts go in and out easily with no shake and no apparent wear. I am going to try the Porter cable screw wax lube I use on the Beall threads to try and prevent rust. Just an experiment for me that I have no idea how it will end and wondering if someone else has already had success or failure trying something similar
Quote from: doc henderson on December 16, 2023, 07:33:05 PM
could reinforce with thin viscosity epoxy, and then retap to stabilize and strengthen.
I was thinking super glue may be another option. Could apply it with a microfiber qtip in a drill but that's just extra work if not really needed.
If it were a few years ago I could give you the strip forces for various screw threads off the top of my head, but that stuff has faded away, there are tables out there though. Usually I figured 3 full turns (threads) on a given screw size gave you the best you could expect for that screw. Now in any hardwood, I would imagine increasing that number of threads would reduce the tearout force per thread.
I suppose for your project and the stated 'playing and learning' it will be interesting to see what you learn. For me, I just prefer using inserts when I need to use machine screws. I do prefer using machine screws over woodscrews for anything that will have to come apart and go back together during it's life, like the removal of a heavy top from heavy legs for moving.
I recently bought a bulk bag of inserts from McMaster for a reasonable price that makes it easy to use them. They have quite a variety available.
I think in wood there will be some variability depending on species and grain orientation.
I guess the way I see it is inserts rely on threads in wood for pull out strength so just going with a slightly larger and longer bolt thread should be equivalent. Now you have me thinking maybe I should pickup a digital torque wrench to get some strip out torque numbers in different woods and grain at different numbers of tightening to see if that diminishes the value by much. The seasonal movement of the mating member will be constant weather threads or inserts that may require some type of spring washer. Would be fun to do a comparison but I think I will try winging it first.
.
I tap many different threads using standard metal taps. After I tap the hole I squirt thin ca glue into the threads, hit with accelerator, and run the tap in a second time. The species of wood does make a difference but walnut, maple, and cherry seldom presents a problem.
I make lots of lamps. This style gets three 10-32 set screws to hold the globe in place.
(https://forestryforum.com/gallery/albums/userpics/10125/DSC_6375~0.JPG?easyrotate_cache=1702779278)
This style gets one 1/4-20 screw to hold the globe on.
(https://forestryforum.com/gallery/albums/userpics/10125/DSC_8393.JPG?easyrotate_cache=1702779277)
(https://forestryforum.com/gallery/albums/userpics/10125/DSC_8395.JPG?easyrotate_cache=1702779278)
Granted the screws only get used when its time to change the light bulb which doesn't happen often.
(https://forestryforum.com/gallery/albums/userpics/10125/IMG_3500.jpg?easyrotate_cache=1702779279)
This is a shop made vacuum chuck for my wood lathe. It's 1-1/4 - 8 and gets installed and removed probably 6 times a week. It has been in use for 4 years without problem.
I also chase threads on the wood lathe for small boxes, and cremation urns. They also get the thin ca trick on the final pass. Wood species does make a big difference when chasing threads.
I also use lots of inserts, but not because they are better. In some places a insert looks more professional than just tapping the wood.
Thanks Larry. I will have to pickup some of the thin super glue to try. I use the gel version now and that doesn't soak in at all. I tried some of my larger metal taps but the chips didn't clear good and damaged the threads especially when backing out. Guess I will try a 10-24 and see how the small ones work because these only go down to 1/4.
great idea with the glass globes. I have about 20 of them that were in the house when we bought it I replaced and was trying to figure out a way to use them. I'm going to steal your idea for the simple base. May try some cherry cookies I have that are dry also.
It is surprising how some materials hold threads well. For my dogtag fixture on my CNC I used 3/4" MDF and I just ran a 10-24x1/2 screw into the MDF. So far it has been holding up great using an M12 impact driver to tighten and loosen the screws.
Here is the full fixture. all those holes were threaded by running a 10-24 into screw into the hole.
(https://forestryforum.com/gallery/albums/userpics/45059/20230204_145051~0.jpg?easyrotate_cache=1702859158)
Closeup
(https://forestryforum.com/gallery/albums/userpics/45059/20230204_145058~0.jpg?easyrotate_cache=1702859159)
and just for an explanation, those blue pieces I 3d printed they are oval pieces that have a relief underneath. I place the dogtag into the pocket the turn those till they sit tight against the tag and tighten the screw. The pockets were machines using a dovetail cutter so there is a nice undercut that holds the tags from lifting on all 4 sides. The fixture is setup to handle business cards and dog tags.
Bits came today and tried the 3/8 and 1/4 threads with accurate holes. Grabbed some 1 inch walnut. Drilled holes, countersink both sides and then threaded. Perfect threads in the walnut. Grabbed a 3/8 SHCS with some washers and tried to strip the bolt out with a standard 5/16 hex wrench. Could not and the washer sunk some in the walnut before I couldn't turn it anymore. Surprised me as I thought the walnut would strip out easily. Put them in and tightened then out 6 times with no damage to the threads. Same with the 1/4 didn't strip after several tightening as tight as I could get them with a std 7/16 wrench. I was afraid to go any tighter with the 1/4 bolts because they are only grade 2 and the heads snap off easily. Now I know they will work for my needs.
(https://forestryforum.com/gallery/albums/userpics/34694/20231222_130339.jpg?easyrotate_cache=1703270442)
(https://forestryforum.com/gallery/albums/userpics/34694/20231222_130355.jpg?easyrotate_cache=1703270442)
(https://forestryforum.com/gallery/albums/userpics/34694/20231222_130526.jpg?easyrotate_cache=1703270439)
(https://forestryforum.com/gallery/albums/userpics/34694/20231222_130400.jpg?easyrotate_cache=1703270438)
(https://forestryforum.com/gallery/albums/userpics/34694/20231222_132102.jpg?easyrotate_cache=1703270435)
(https://forestryforum.com/gallery/albums/userpics/34694/20231222_131750.jpg?easyrotate_cache=1703270434)
(https://forestryforum.com/gallery/albums/userpics/34694/20231222_132217.jpg?easyrotate_cache=1703270432)
That will work. can you try a piece of pine?
Quote from: Crusarius on December 22, 2023, 04:25:40 PM
That will work. can you try a piece of pine?
I don't think I have any pine. I'll dig out a piece of cottonwood that seems even softer then pine.
Had some 7/8 cottonwood and used the 3/8 tap. Drilled 2 of the hardwood size pilot holes and 2 of the softwood size pilot holes. Threads are not as clean and sharp as harder wood. The 3/8 SHCS bolt stripped out the hardwood size taps with a good tightening. The softwood size holes also stripped out but it took twice as much force as the first set. I bet at an inch thick wood would hold them pretty good but I think an impact driver will strip them in any type of wood if you're not careful.
(https://forestryforum.com/gallery/albums/userpics/34694/20231222_183524.jpg?easyrotate_cache=1703288753)
(https://forestryforum.com/gallery/albums/userpics/34694/20231222_183538.jpg?easyrotate_cache=1703288752)
One learns so much from testing, I'm glad to see your results. About the same as what I have experienced.
I ordered the 9 pcs master set with 6 SAE and 3 metric.
I almost got the full set but metric hardware is quite pricey so just got the ( 6 ) inch size for now. They do work nice in hardwood. Just like tapping metal a little countersink on both sides of the hole makes for clean threads with the tap easier to start. Sorry for being a bad influence but they do work nice.
Thanks 21, thats really helpful.
My wife wants a little bench for by the door. I grabbed a walnut cutoff and flattened it with my flattner then planed it and started hacking the ends to go with the live edge. Decided that I will blind tap the board and bolt legs in place to see if the threads will hold up. Funny thing is I think that Amazon thing is listening to us because I went to Amazon and a pair of clearance Chinesium bench legs popped up for $18 so I just bought them and don't have to make my own. Won't be here for a week though. I played with 1/4 blind taps to mount them in scrap that look like they will work. Busted one open and the threads don't look bad. Impact driver works on #1 but #2 strips them right out at 3/4 inch depth. Put a drop of super glue in the threads before inserting the bolt and it's permanent. Need to find some kind of applicator like a uhmw bolt that the glue won't stick to. I'm going to try the bench first and see if they can stand up to my fat butt. ;D
(https://forestryforum.com/gallery/albums/userpics/34694/20231223_132729.jpg?easyrotate_cache=1703357033)
(https://forestryforum.com/gallery/albums/userpics/34694/20231223_132746.jpg?easyrotate_cache=1703357033)
(https://forestryforum.com/gallery/albums/userpics/34694/20231223_132847.jpg?easyrotate_cache=1703357030)
Just finished up a small bench for my wife made from a walnut cutoff and clearance legs from Amazon. Got. 2 sets for 18 bucks.
(28) 1/4-20 SHCS give it a real primitive industrial look. My under $10 bench that will probably last forever and my wife is happy. Next to dig out a big walnut slab for the second set of legs.
(https://forestryforum.com/gallery/albums/userpics/34694/20231229_130904.jpg?easyrotate_cache=1703873718)
(https://forestryforum.com/gallery/albums/userpics/34694/20231229_130918.jpg?easyrotate_cache=1703873717)
(https://forestryforum.com/gallery/albums/userpics/34694/20231229_130935.jpg?easyrotate_cache=1703873715)
A quick couple hour project with no frustration or complexity to end the year.
subtle and beautiful. I really like those legs.
21 what did you use to make the large radius round over on the ends?
Quote from: Crusarius on December 29, 2023, 01:57:56 PM
subtle and beautiful. I really like those legs.
I was surprised to get 2 sets because I thought it was 2 legs or one set. They are nice but the ground area where they are welded shows unevenness in the paint. Going to repaint them with hammer tone paint when it warms to hide that. I think that Amazon thing listens to us because I was talking about buying some cheap legs and all of a sudden this deal popped up :o
Quote from: doc henderson on December 29, 2023, 02:12:05 PM
21 what did you use to make the large radius round over on the ends?
I started with power plane then went to a spokeshave followed by the Shinto file and then sandpaper. Tried to make it vary some to go with the natural edge. I just bought a 3d CAM package that I am going to try and work out a more natural looking random one that I can do on the cnc router in the future.
can you provide a link to the legs?
Quote from: doc henderson on December 29, 2023, 02:47:52 PM
can you provide a link to the legs?
I went back to check and it says no longer available so it looks like I got the last ones on clearance. I was going to buy every set they had left :o. Amazon has similar ones by different vendors but they are in the 37 to 40 dollar range for a set if you search. Not fancy but good for utility stools and tables. I wanted Ritelegs but it's the end of the year budget that won.
I had too and did not find those. however, my 9-piece set of taps came in today! same infinity brand.
A lot of Amazon users do not know about Amazon Warehouse. I always go there to see if they have what I am looking for. Most of it is returned stuff. "Used like new" is usually an opened package. I have only had an issue once where someone had repackaged a used part as new. The same Amazon guarantee applies so if its in rough shape or not what I want, I just drop it off at the local UPS store and they refund me, no repacking required. It is usually 20 to 30% off. I usually skip the lower categories like "Used Acceptable" The thing to be aware of is that it is not just Amazon selling used, some manufacturers also list items and sometimes their prices are higher than new. Most of my best deals are the small stuff, I needed a mechanical twist timer for 120 VAC, I got a GE version for half the price of new one.
Well, I really prefer the Rite Legs and almost always use theirs, but I did have a client specifically request hairpin legs, so I found a company and they are not bad, they started making tube and flat steel legs last year, but I just checked and their prices are getting up there from when they started with these.
I'm not pushing somebody else over Rite legs, but the company is called hairpinlegs.com. Again there quality is 'ok' but not on a par with the Good guys. Also, there is a secret room at logrite nobody really knows about. When I order big legs I often drive over to pick them up, it saves on shipping and also wear and tear on expensive legs during shipment. When I am there I ask Shaina very nicely if I can peek in the room and have found some discontinued or scratched items they can make me a little deal on. But don't tell anybody about that please.
I couldn't even buy the paint for what ya paid for those legs. I'll take a 1,000! My only thought is if the holes are big enough to allow for a little seasonal wood movement.
That's a good looking stool and I like the finish, is it oil?
Quote from: Larry on December 29, 2023, 09:12:42 PM
I couldn't even buy the paint for what ya paid for those legs. I'll take a 1,000! My only thought is if the holes are big enough to allow for a little seasonal wood movement.
That's a good looking stool and I like the finish, is it oil?
With free 3 day shipping from California. Guess they may be trying to dump inventory of items there are only a couple left of before the end of the year. I am relying on the legs flexing for movement. I only have 1/16 of clearance total in the holes but I think the Chinesium will flex because it's very thin wall tubing. If not, I can machine slots . I figured less then 1/8 movement in the 11 inch span.
The first set of holes is 6 inches apart so I used 6 x .0027= .0162 and I see about 9% to 12% in my wood content seasonal so I went with a 3% swing .0162 x 3= .0486 so that's what the first holes should shift under ideal conditions seasonally. Time will tell but I think the flex will handle it. If not, I have some firewood and an education.
I use Polycrylic on everything. Here's a video about making it showing how I get a fast non glare finish with the gloss Polycrylic. I don't like the tint of the satin one and my wife can'tstand outgassing of oil finishes..
Quick And Easy Live Edge Walnut Bench Build Using Commercial Legs - YouTube (https://youtu.be/CRDam8LXuBg)
I was surprised to see you using a foam brush with the polycrylic. Foam brushes will cause bubbles in the finish. Anytime I have tried to use foam I end up sanding it off and redoing it with bristle brush.
Overall that bench came out real nice. Got me thinking about the wood taps now.
Do you think you could skip the johnson paste wax step and still get the same results?
I think I should get some beeswax and start playing with that.
My go to finish lately has been danish oil but the smell is terrible. Part of the reason I love the danish oil is the way it brings the grain out. I have never been able to get the same results with just the polycrylic.
Try using sanding sealer. It's not cheap, but it goes a long way. It makes all the fibers stand up to be sanded and also seals the wood, saving extra coats of finish. It dries fairly quick, put it on, et it dry, hand sand it with 220 paper (it goes quick), then apply your finish. I don't use it on everything, but when I do, I get nice results faster.
Quote from: Crusarius on December 30, 2023, 09:12:30 AM
I was surprised to see you using a foam brush with the polycrylic. Foam brushes will cause bubbles in the finish. Anytime I have tried to use foam I end up sanding it off and redoing it with bristle brush.
Overall that bench came out real nice. Got me thinking about the wood taps now.
Do you think you could skip the johnson paste wax step and still get the same results?
I think I should get some beeswax and start playing with that.
My go to finish lately has been danish oil but the smell is terrible. Part of the reason I love the danish oil is the way it brings the grain out. I have never been able to get the same results with just the polycrylic.
That's all I use for the Polycrylic. Dip the brush on the opposite side of the can that you wipe it on. I cannot get the same results without a solvent paste wax first (trying to find a substitute though because of the temporary solvent smell). Don't know what it is but the wax makes the Polycrylic degloss best without tinting and in about 30 days it hardens into a very durable finish. The secret seems to be sanding off the first 2 coats good and a thin final coat so it doesn't look like a plastic layer. I found Danish oil doesn't have the durability of Polycrylic after its cured.
Quote from: Old Greenhorn on December 30, 2023, 09:43:10 AM
Try using sanding sealer. It's not cheap, but it goes a long way. It makes all the fibers stand up to be sanded and also seals the wood, saving extra coats of finish. It dries fairly quick, put it on, et it dry, hand sand it with 220 paper (it goes quick), then apply your finish. I don't use it on everything, but when I do, I get nice results faster.
I tried that and find that I have better results with just using the polycrylic to raise grain and not affect the clarity on walnut. With polycrylic it takes about 6 hours start to finish including drying time and one can of finish so I stick with that. oaks are a different story with big pores.
I agree with the durability thing. If I am worried about it I will use satin polycrylic over the danish oil after it stops off gassing.
Threaded wooden bolts in a table swift. The one on the left clamps the swift to a table. The one on the right supports the open umbrella. Made it 13 years ago. Still use it once in a while if I get skeinned yarns, they need to be wound onto spools or pirns for shuttles on the loom.
(https://forestryforum.com/gallery/albums/userpics/11009/table-swift-screws.jpg?easyrotate_cache=1703960799)
Got the 3 metric taps and finally got them organized. Designed and 3d printed a holder for them to fit into one of the compact organizers then started playing with the Kaizen foam in the bottom half of the organizer. That stuff is a real pain to work with. Can score with my laser but makes a mess if I try to burn through. Bought a bunch of sheets of it and now think I am going to have to make a hot wire cutter for all the packout drawer inserts.
(https://forestryforum.com/gallery/albums/userpics/34694/20240110_185121.jpg?easyrotate_cache=1704931483)
(https://forestryforum.com/gallery/albums/userpics/34694/20240110_185155.jpg?easyrotate_cache=1704931483)
I got the 9-piece set with 6 sae and 3 metric. taps. may have to contract with you to make me one. :)
One thing to remember Doc is the drill size on the label is for softwood. Supposed to go approximately 1/32 oversized for hardwood. I made some labels to remind me because the first try with sharpie rubbed off the container
(https://forestryforum.com/gallery/albums/userpics/34694/20240111_090155.jpg?easyrotate_cache=1704984613)
(https://forestryforum.com/gallery/albums/userpics/34694/20240111_090228.jpg?easyrotate_cache=1704984615)
I stuck another set underneath because I know labels get damaged. Wish they sold a matching set of bits for them.
Round 2 will have storage for the bits under the taps.
I go to a "big tool store" in derby. I bought a nice set of quality bit. they also sell the same brand to replace any that break or are lost. you could try a shop like that. Let me know if you want to export one of those.
I see countersinks. what are the other items in your kit?
I always make a test thread in a piece of scrap from my project. Use the same grain orientation. I've found bit size can vary between species of hardwood. Especially important with small threads. I'll use number size drills to get the perfect hole. I'm using standard metal taps and they are probably not as good as 21's taps.
I picked up this low end Fisch set that are pretty good. I wanted the higher end set but didn't want to spend the $300.00. So far the hole sizes they call for have worked good. Doc those other blocks with the holes are the big gator drill guides. I always use them for perpendicular holes when drilling by hand. I also have their tap guides for metalworking.
(https://forestryforum.com/gallery/albums/userpics/34694/20240112_184559.jpg?easyrotate_cache=1705104496)
nice set in a brad point. what are the round collar things, depth stops?
Yes they are just cheap clamp on drill stops. I didn't want to use the old set screw stops on these bits. I used to use painters tape but somehow it could slip and allow break through turning a project into firewood. The bits aren't the best and leave some fuzz going in but leave a nice clean hole. Their good set has much longer burrs for a cleaner start.
Dewalt has some nice brad point, pricey. Also Lee Valley has even better. Again pricey. I also have a set from Festool (Lee Valley purchase) with hex shanks that are good to. Drilled a lot of holes this winter 1/4" into maple, no tear out. Only set on top of cardboard. Can't say that a couple lag bolts didn't tear a little though. ;D I never even put nuts on the bolts, that's how stable it is. But I only built a prototype of what I am using for now. It's a 'draw bridge' on the loom. Weaving lingo, it's a lot like science fiction: warp, shuttle, bridge that sort of thing. Warp six yards, make it sew number one. I'm giving it all she's got, but it just won't sew, Captain. I can only get it to weave. :D :D
The Lee Valley bits are some of the best. They buy high carbon USA steel bits and regrind them to their specs. The Fisch bits are supposed to be made in Austria but there is no country of origin anywhere on the packaging and they look like and cut like higher end Chinese bits to me.
Got a link to this video in my email this morning. Guy runs strength tests on wood inserts versus direct wood threads.
https://www.youtube.com/watch?v=S4SnrbGwGpI
It was interesting. The comments were just as interesting as the video with lots of pro's and cons.
Nice video Larry, short and to the point. Of course, it's not comprehensive, just more of an entry level study, and an eye opener for some.
One other aspect of this whole question for me is the TYPE of insert used. Those inserts in the video are more of a general purpose insert for several materials including wood. If I am not mistaken, they have a standard larger thread on the OD that can be tapped into other materials. Also note, if used in an application where the insert can be installed from the farside then that flange adds a lot to pull out strength. That's not often possible though.
The inserts I use, and RiteLeg sells have interrupted threads which cut deeper into and wood and they have no flange, so no countersink is required. I'd be very curious to see a comparison between insert types, that would be neat.
I also found the addition of CA glue helped with the cut threads and hurt with the inserts, that was odd.
Knowledge is power.
That video and comments are really interesting.
I would not have thought that tapping that small a thread in wood would work.
I do have some larger taps.........If I can scrounge up bolts.
I wonder if there is a difference between fine and coarse threads.
I have 2 - 35mmx3 bolts but no tap
I Know I have a 1/2-13 tap and some bolts, or 3/8- 16, and might have some 3/4-10 bolts
How much till its extreme overkill
I watched the video early this morning and found it really interesting, along with the comments. People who do destructive testing are right up my alley. I side with the penetrating epoxy for direct threading into wood.
Another way we go is with bronze nuts and washers, carefully glued together, then snugged into a hole, either for compression or tension, depending on the build. You need to know what you want before buttoning things up- If they're to be on the inside of a torsion box or other assembly. After the nut washer assembly is snugged in, I float it with epoxy and apply some thread lubricant. This kind of construction is reserved for clients who appreciate it, or in marine settings.
There is also a bottle of aqueous solution carnauba wax in the pic that can be purchased directly online. No smell. We buy this by the pallet and re-sell to our ongoing customers. The little can is thread lubricant, specifically for bronze hardware. If you gently heat the threads and touch it to the lubricant, you get a nice micro sheen that works quite well. In setting expensive hardware, I always build a jig with orientation face up, face down, etc. That helps take the guess work out.
I'll have to look for that screw lubricant. I have been using a Porter cable screw lube stick since the 1970s and its almost gone. My fat butt does most of my destructive testing ffcheesy.
Now that I have been using the wood threads for a while, I will never go back to inserts for hardwood. The taps are holding up fine so far.
I have used wooden threads and bolts of maple on a swift here for 12 years. One acts as a vice and the other holds the umbrella open. Works great for me. ffsmiley