# Using threaded inserts



## msbeal (Oct 3, 2010)

I recently purchased some steel threaded inserts from Rockler.com. I've never used them before and needed some screw down knobs in a jig I was building. 

I drilled the recommended guide hole and you're supposed to use the screw driver slots on the top to screw them down into the hole in the wood. 

My problem is they kept cantering off axis to the right on me, mainly because I'm right handed I figured. I couldn't see anyway to control stopping them from going off plumb or off perpendicular to the wood surface. Both my knobs lean to the right now. Ugh. 

I was going through some hard maple and considered increasing the guide hole but was afraid I'd lose holding power. 

Anyone know of a solution to using these? Is there a tool that helps you put these things in?


Any suggestions?


----------



## Paul 649 (Feb 14, 2012)

msbeal said:


> I recently purchased some steel threaded inserts from Rockler.com. I've never used them before and needed some screw down knobs in a jig I was building.
> 
> I drilled the recommended guide hole and you're supposed to use the screw driver slots on the top to screw them down into the hole in the wood.
> 
> ...


Use your drill press, chuck up a tool that fits the slot in the insert and apply light pressure downward towards your hole and turn the drill press quill by hand till you get it started good.


----------



## phinds (Mar 25, 2009)

I always insert them by putting into them a short hex-head bolt and turning that with a ratcheted driver.


----------



## woodnthings (Jan 24, 2009)

*that's a good tip*

I would add using a jam nut on the bolt and have enough length to see what you are doing. A deep well socket and a "T" handle would be my preference. A nut driver with a center hole for a headless bolt will also work. This would be a dedicated "tool" but real easy to make. The hole in the nut driver for the shaft of the bolt will give you additional giding leverage to keep the insert going in straight. 

Probably if you went up 1/64" in hole diameter in the hard Maple it wouldn't give less integrity IF that was necessary. Better than canted inserts in my opinion. :laughing:


----------



## cabinetman (Jul 5, 2007)

The proper sized drilled hole should be *perpendicular* to the stock. When drilling I use a clean out pass to clear any debris. To install the insert, I use a machine bolt with the same thread as the inside of the insert. The head can be any type as long as it's a hex drive as Paul suggested.

The length of the machine bolt could be a few inches, which gives you a good visual of what's happening. Double nut the bolt threads. I use a hex key (AKA allen wrench) to insert. A power driver is a bit fast...even on slow speed.


















.


----------



## BWSmith (Aug 24, 2010)

We run Taps in first.You'll have to play with hole size....different woods,different grain patterns will require a little different pilot hole.

With but a few exceptions,you can tap woold just like metal.The problem isn't that you can't just run an insert into the called out pilot hole...the issue is about the wood's compression when doing so.By runnin a tap in there....and you can experiment with the depth....you're cutting away a little wood,but really getting things lined up.

Look at "plug taps"...their taper'd leade ins are designed to do exactly what's causing you issue.Good luck.

PS,with a good DP and a cpl fixtures...you can make your own inserts,utilizing store bought bolts.You just need to drill/tap them in the center.This is for special purposes.....

PSS,if you need really straight insert location....using DP is a gimme.One of the "tricks" is however....once you've drilled pilot hole,leave your wood in vise/fixture.Now take drill out of chuck and replace with a straight pce of drillrod or sumthin.Sharpen the end of this pce.It fits into the "center hole" on the end of tap.Now since you didn't take part out of fixture everything should be pretty durn lined up.

A nice tap handle works wonders in this dept.With part still in fixture,table height adj....tap handle needs to be as long as it can be,and still clear column.Now,stand back and look at the handles relationship to the table...and the part.The handle should be horizantal,and at a 90* to tap.You can check in both axis.This is a super quick setup trick.If for instance you already had the hole.....but need to center it for tapping.Throw that handle up there and look at it.I'll bet on accuracy rivaling extremely sensitive instruments and it takes less time than writing about it.Good luck.


----------



## tt1106 (Apr 10, 2009)

If you cut the head off a bolt that fits. Chuck it up in your drill press and hand screw it into the stock. I've also found that the T-handle insert wrench (Got mine at Woodcraft, I believe) works great at helping screw it in straight.


----------



## cabinetman (Jul 5, 2007)

BWSmith said:


> We run Taps in first.You'll have to play with hole size....different woods,different grain patterns will require a little different pilot hole.
> 
> With but a few exceptions,you can tap woold just like metal.The problem isn't that you can't just run an insert into the called out pilot hole...the issue is about the wood's compression when doing so.By runnin a tap in there....and you can experiment with the depth....you're cutting away a little wood,but really getting things lined up.
> 
> Look at "plug taps"...their taper'd leade ins are designed to do exactly what's causing you issue.Good luck.


I agree that wood can be tapped with regular machine screw thread taps. There are tapered ends and flat ends. These would likely work if the threads on the threaded insert were the same as the tap. But, IIRC, the threads on the threaded inserts are a coarse cutting thread, designed to cut one time into the wood. With the hole drilled sized approximately the diameter of the shaft of the insert, that leaves the threads to cut into the wood...the depth of the threads. Their effectiveness is predicated on that arrangement. I could be wrong.

















.


----------



## BWSmith (Aug 24, 2010)

Taps/inserts come in many sizes.They're not limited to what 's stocked in WW stores.

An effective...if not,down right easy "tap" can be made with a bolt.Take a cutoff wheel in a die grinder(dremel works fine)and cut a lengthwise flute,a "slot" if you will.Cut it slightly in the direction of travel....meaning,you want it to have a slight positive rake.Look at a regular tap....cut the flute on the bolt to reflect the cuttin geometry of that.It won't be perfect,but then,you could buy a cpl bolts and practice?

You can conceivably make a tap out of an insert...same thing,make a cutting flute with a diegrinder/dremel.

Be aware that storebought inserts are "generally" center'd.Not going into the details but at least give them the "once over" if it's a critical location.


----------



## Dave Paine (May 30, 2012)

msbeal said:


> I recently purchased some steel threaded inserts from Rockler.com. ......
> 
> My problem is they kept cantering off axis to the right on me, mainly because I'm right handed I figured. I couldn't see anyway to control stopping them from going off plumb or off perpendicular to the wood surface. Both my knobs lean to the right now. Ugh.
> 
> Any suggestions?


I am intimately familiar with this issue.

It is the insert, not you. They will go askew unless you prevent this, which takes some effort.

The screwdriver is not going to help.

You can purchase drivers for the inserts.

http://www.leevalley.com/US/wood/page.aspx?p=65133&cat=1,180,42334

If you do not want to purchase a driver, use a piece of threaded rod and two nuts locked to each other.

One end of the threaded rod goes in the insert, to the bottom.

The other end goes into your drill press. Lower the chuck and set the height. Tighten the chuck so the threaded rod can rotate but not wiggle.

Clamp you board so it will not move.

Now use a wrench to screw in the insert. The chuck will keep the threaded rod perpendicular.

When the insert is installed, release the two nuts.

My first time I used a short bolt. The problem was when I came to unscrewed the bolt, it brought out the insert. Hence I now use two nuts.


----------



## TomC (Oct 27, 2008)

Take a piece of thread rod with the same threads as the insert threads. First thread a jam nut on the rod and then thread the insert on the rod. Bring the jam nut up against the insert. Chuck the other end of the rod in your drill press. Turn the DP chuck by hand as you apply a slight down pressure on the DP. All you need to do is get it started straight and then you can fully install with a screw driver. I have done this on a wood lathe and it should work OK a drill press. I didn't have a threaded rod so I cut the head off a bolt.
Tom


----------



## msbeal (Oct 3, 2010)

*threaded inserts*

Bravo to all! An excellent collection of good ideas. Truly

It does confirm my first suspicion that these little guys aren't going to go in as easy as any screw with a stupid screw driver. I'm going to complain to Rockler that they should give a guy a technical warning or a video or something. 

On my own I did run across the idea of tapping the treads first. No matter how you accomplish it, that sounds like the cleanest solution. I think doing it by hand, with a cut off bolt inserted into the insert might give one more control. 

I'm going to look around and see where I can use these again just for the fun of trying these solutions. 

I thank you one and all.


----------



## Dave Paine (May 30, 2012)

msbeal said:


> On my own I did run across the idea of tapping the treads first. No matter how you accomplish it, that sounds like the cleanest solution.


The nuance with tapping for the insert is that it may be an unusual thread.

I just checked my Rockler inserts and they are 12 tpi but 1/2in dia. My tap and die set has 1/2in dia x 13 tpi or 9/16in dia x 12 tpi. Bummer.


----------



## dwl (May 28, 2009)

Paul 649 said:


> Use your drill press, chuck up a tool that fits the slot in the insert and apply light pressure downward towards your hole and turn the drill press quill by hand till you get it started good.


This does sound like a good tip, thanks I think I will try this in the future.


----------



## GROOVY (Apr 27, 2008)

Another idea, I think it is important to file off the top threads of your insert driver. That way it can screw all the way into the insert and can be backed out. I put a bit of wax on both. The flathead screw slots in the inserts are worthless...


----------



## Al B Thayer (Dec 10, 2011)

For maple I use bees wax on the threads. Using the bolt method you can eyeball it after a turn and tap it straight and continue. No big deal.

Al

Nails only hold themselves.


----------



## Chaincarver Steve (Jul 30, 2011)

GROOVY said:


> ...
> 
> The flathead screw slots in the inserts are worthless...


So true, especially on the brass inserts. The slotted parts seem to strip and chip out at least as often as not.


----------



## unclefester (Aug 23, 2013)

I've used the Woodcraft driver for the inserts and have had the problem of backing the insert out with the tool. I like the idea of tapping the wood first with a bolt in drill press. 

Thanks for the suggestion.


----------



## msbeal (Oct 3, 2010)

*Tapping the hole first*



unclefester said:


> I've used the Woodcraft driver for the inserts and have had the problem of backing the insert out with the tool. I like the idea of tapping the wood first with a bolt in drill press.
> 
> Thanks for the suggestion.


I went and looked for a match set of drill bits and taps (I think that's what they call them) and I reached the conclusion you probably have to buy the bit and tap per the job you're doing. Apparently the drill bit and tap are a matched set and you're have to match the thread count for that to work. 

However I end up doing my next one, I feel much better armed knowing what I'm up against thanks to all this good info here.


----------



## cabinetman (Jul 5, 2007)

msbeal said:


> I went and looked for a match set of drill bits and taps (I think that's what they call them) and I reached the conclusion you probably have to buy the bit and tap per the job you're doing. Apparently the drill bit and tap are a matched set and you're have to match the thread count for that to work.
> 
> However I end up doing my next one, I feel much better armed knowing what I'm up against thanks to all this good info here.


My suggestion is this...that if the hole is drilled to the correct diameter, the insert is designed to cut into the solid sidewalls for it's holding power. If you tap the hole, you've changed all that.


















.


----------



## Al B Thayer (Dec 10, 2011)

I've never seen something so easy become so complex. Been using inserts for 2 decades. Once in a while I might take the drill size up if I had maple. Bees wax will cure any problem posted in this thread. Don't think anyone is selling a thread cutter to fit the insert. Most likely your just making the hole larger therefore allowing the insert to go in easier. 

Al

Nails only hold themselves.


----------



## cabinetman (Jul 5, 2007)

Al B Thayer said:


> I've never seen something so easy become so complex.


Well ain't that something.:yes:








 







.


----------



## FrankC (Aug 24, 2012)

msbeal said:


> I went and looked for a match set of drill bits and taps (I think that's what they call them) and I reached the conclusion you probably have to buy the bit and tap per the job you're doing. Apparently the drill bit and tap are a matched set and you're have to match the thread count for that to work.
> 
> However I end up doing my next one, I feel much better armed knowing what I'm up against thanks to all this good info here.


There are charts that tell you which drill to use for each size and TPI of the thread. For metal work Numbered and Lettered bits are used as well as fractional sizes.
http://www.boschtools.com/SiteCollectionDocuments/1666.pdf

Using a tap, if you could find an identical thread, will likely present the same problem as simply threading the insert unless you use some kind of guide, which is fairly common practice in metal work.


----------



## Sleeper (Mar 24, 2009)

I’m about to use a 1/4x20 insert in Red oak and I was wondering how strong they are. Is there a reference chart showing what the pull out pressure is?

I may not be using the proper terminology and I hope you know what I mean.


----------



## cabinetman (Jul 5, 2007)

Sleeper said:


> I’m about to use a 1/4x20 insert in Red oak and I was wondering how strong they are. Is there a reference chart showing what the pull out pressure is?
> 
> I may not be using the proper terminology and I hope you know what I mean.


Drill a nice clean hole recommended for the insert you have. Don't tap the hole. Install the insert once, and you'll likely not be able to pull it out.








 







.


----------



## Sleeper (Mar 24, 2009)

cabinetman said:


> Drill a nice clean hole recommended for the insert you have. Don't tap the hole. Install the insert once, and you'll likely not be able to pull it out.
> 
> 
> 
> ...


Thanks I just pulled mine out that I bought from Mcfeelys.com and they use a 6mm Hex Drive. I wish I would have noticed that earlier because I need to buy one. 










I don't have a lot of metric tools only the basic wrench and socket set.


----------



## FrankC (Aug 24, 2012)

If you are doubt about the holding power and it is an insert with an open bottom drill a 1/4" hole through the board, then enlarge hole and install inserts on back of board.


----------



## Sleeper (Mar 24, 2009)

FrankC said:


> If you are doubt about the holding power and it is an insert with an open bottom drill a 1/4" hole through the board, then enlarge hole and install inserts on back of board.


That will not work fo me because the only reason I'm using an insert is because i don't want anything shown on the other side otherwise I would just use a nut and bolt.


----------



## BWSmith (Aug 24, 2010)

Heck,it ain't complex....we use a Bridgeport milling machine and get them spot-on everytime.But then we make our own inserts....the factory stuff usually comes up short in the engineering part.We make them out of Brass,Aluminum,and steel.It goes on installs where design calls out different materials,custom inserts*.They're quite often being installed in some rather nasty,very hard woods.......just can't risk not tapping here?

If you've never tapped a hole I reckon it could be called complex though?It only takes 10 or 15 seconds in wood?Usually takes us longer to fixture the part......so adding the tapping adds very little to the overall time involved?Certainly not worth the mistake when things aren't as easy as you'd like it?

*Custom inserts;some times we do inserts that aren't threaded.They're shoulder'd and installed with a big H-frame press from back side of pce.We turn grooves in the main body to allow for glue.Then there's rifle stock work.These are pillars......this is pretty hard for some to understand but....the accuracy in the woodwork on custom rifles has to be very high.You get a pillar off by a cpl .001's and see what the customer has to say about it.

Many ways of looking at WW.To some its a hobby that is to be enjoyed.......the fact that it has a high degree of accuracy escapes some folks?


----------

