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Threaded brass insert installation

rons

Diamond
Joined
Mar 5, 2009
Location
California, USA
Here is the subject:

https://www.homedepot.com/p/Everbil...Brass-Wood-Insert-Nut-2-Pack-818798/204806598

A side issue is that wonderful price for 2 pieces. I have seen a pack for 25 pieces go for between $6 - $7. Home Depot :icon_bs:

I insert these with a short hex or allen head 1/4-20 screw. A 1/4-20 nut is turned all the way to the end of the screw thread. Then
the screw is turned into the brass insert. Take a hex key shank and insert into drill press chuck. Then use a few manual turns on the
chuck to start the insert into the wood. Tried a few times to use a slotted screw driver but the insert always gets ugly looking.

The notch is there just to get mangled by a slotted screw driver. It's only going to be strong enough in steel inserts. Removing a
a insert would be easy if there was a way to screw in a 1/4-20 screw that was modified in some way to apply force at the bottom of
the insert will turning counter-clockwise.
 
Here is the subject:

https://www.homedepot.com/p/Everbil...Brass-Wood-Insert-Nut-2-Pack-818798/204806598

A side issue is that wonderful price for 2 pieces. I have seen a pack for 25 pieces go for between $6 - $7. Home Depot :icon_bs:

I insert these with a short hex or allen head 1/4-20 screw. A 1/4-20 nut is turned all the way to the end of the screw thread. Then
the screw is turned into the brass insert. Take a hex key shank and insert into drill press chuck. Then use a few manual turns on the
chuck to start the insert into the wood. Tried a few times to use a slotted screw driver but the insert always gets ugly looking.

The notch is there just to get mangled by a slotted screw driver. It's only going to be strong enough in steel inserts. Removing a
a insert would be easy if there was a way to screw in a 1/4-20 screw that was modified in some way to apply force at the bottom of
the insert will turning counter-clockwise.

Could you simply switch to a knurled OD threaded insert, and use some epoxy to hold it in place ?
 
McMaster sells very nice brass inserts and an installation tool. If you drill the proper size and use the tool, should go well.

I generally apply beeswax to make the process go smoother and also generally clamp the wood to prevent splitting in smaller parts.
 
Switch to an insert with an internal hex wrenching surface. McMaster has them for hard wood or soft wood.
McMaster-Carr

McMaster also sells installation tools for the type od insert you have been using. They are listed with the insert assortments.
 
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That slot on the end of that type insert is not for a screw driver. That is the inserted end, and the slot allows the end to cut the thread more readily. You drive the fitting in with a bolt having a pair of locked nuts to bear against the top of the fitting.
 
You'll find confusion abounds with these inserts. The type you linked to in your first post go in with the slotted end first, as previously noted. There are other types of inserts with a shallower slot, which are meant to be used with a special driving tool, like this:

51iMWbx2VtL._SL1000_.jpg

If you use a screwdriver on an insert, especially with the brass inserts with a shallow slot, more often than not you will mar the fastener by camming out the tool as it gets tight in the hole, and possibly the surrounding surface. It's not a pleasing outcome.
 
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Damn, I've been putting mine in upside down all these years! I figured out a long time ago to drive them with a bolt and stop nuts, but never realized the slot was there to cut threads.

Chris, thanks for the info,
 
I've had to have a few battles with those inserts, high-stress stuff in the final days of build, so it took a while to work out how those inserts work. That damn slot just conveys the 'use screwdriver' to most folks I expect.
 
Placed a 1/2 diameter insert on end with slot facing up. Examined insert looking down at 50x. It ford look like the sharp edge of the slots would sheer off wood.

But in every wood that I have used inserts the bore hole is slightly larger and an academic would say that the 1/2 diameter insert in a slightly larger diameter
hole will not have the sharp edges of the slots in contact with wood. Or does the bore hole stay at 1/2 diameter and just drive the insert? Have not tried the
slot down method yet.
 
Yes Chris, the slot is an "attractive nuisance". And as rons noted, there is a lot of contradictory info out there, even on manufacturer sites.

My usage predates the internet by decades, so I have no one to blame but myself.
 
Placed a 1/2 diameter insert on end with slot facing up. Examined insert looking down at 50x. It ford look like the sharp edge of the slots would sheer off wood.

But in every wood that I have used inserts the bore hole is slightly larger and an academic would say that the 1/2 diameter insert in a slightly larger diameter
hole will not have the sharp edges of the slots in contact with wood. Or does the bore hole stay at 1/2 diameter and just drive the insert? Have not tried the
slot down method yet.

Does the slot intersect the external threads? Seems like that's the only way it could cut them. I'm not at the shop so I can't examine mine.
 
Ron,

I strongly suggest you experiment with placing inserts into a block of scrap first, to sort out the correct hole sizing for the insert you have. With wood, as it can vary tremendously between species in crushing resistance, fiber length, etc., (not to mention placing inserts in materials like plywood, mdf, etc.) there is no set rule as to the relationship of hole size to insert threads. You want the insert to be firmly in there, not so firmly that you are looking for a cheater bar, and not going in so easily of course that it is loose or easily unscrewed. It's less than entertaining to put something together with an insert and a fastener, and then want to take it apart only to find the insert spinning out because it was in too loose.
 
Here is the subject:

https://www.homedepot.com/p/Everbil...Brass-Wood-Insert-Nut-2-Pack-818798/204806598

The notch is there just to get mangled by a slotted screw driver. It's only going to be strong enough in steel inserts. Removing a
a insert would be easy if there was a way to screw in a 1/4-20 screw that was modified in some way to apply force at the bottom of
the insert will turning counter-clockwise.

If you put a wrench on the jam nut and keep it snug against the top of the insert while removing it will work. Takes 2 hands and a bit of coordination to get the competing torque values just right but it can be done.
 
In my experience the insert goes in easier with black walnut or mahogany. Ash and oak are the tough ones. I know there are tougher ones.

I used this joint in a glass table base to match some Danish designed teak wood chairs. The insert is just a short bar with a thread through
the middle. There is a brass flat head hex bolt that holds the joint closed. Could have used a insert but the chairs used this joint.
The maid does not come until tomorrow to do the dusting...

DSC_1032.jpg
 
I'm beginning to doubt that the long slotted end of the insert is for the purpose of cutting a thread. Thread cutting - tapping - isn't necessary in wood as the steel thread works fine on its own to compress what it needs to and form a grip with the material. That said, I have used taps in really hard woods , like ebony. Perhaps it is more the case that the slit end of the insert can deflect slightly inward as it goes in the hole, easing the path of the insert into the hole. The slot enables the side walls to self taper slightly.

It doesn't make sense as a screwdriver slot, despite appearances. Of course the brass ones readily break - steel ones can as well I have found, but it is not shaped for the fit of a normal screwdriver tip. And in cases where the insert is exposed to view, then it looks cleaner with the slotted end buried I would say. And on top, I'm generally not intending an insert to be a removable item, but a permanent one. If you drive it in there snugly using a bolt and doubled nuts, leaving the slotted end up, thinking it will be easy to remove with a screwdriver later, then you may find the top of the insert splitting as you try to unscrew it and you get to play the 'remove the broken insert game'.
 
That slot is probably for a dedicated driving tool like your picture in post #7. A slotted screw driver will not fit correctly and will chew up the slot,
especially a brass slot. Yesterday I was looking at a page that had a slot up insertion with a red cross over the picture meaning that the slot side goes in first.

I started this question because I removed a bunch of inserts from some project wood and I had to chisel them out. If I had tried with a screw driver
the inserts would have been ruined.
 
I use them with the tool Chris posted using the approach that I posted above, in hardwoods. Works fine. I notice the threads typically appear burnished so the fastener is likely forming the threads rather than cutting them.
 
These require a screw driver with a parallel grind to the tip, not a wedge.

Even still, whatever they say if you don’t use the proper setup that top is going to sheer right off.
 








 
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