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1/4" -20 Threaded Inserts (8 per Pack)
1/4" -20 Threaded Inserts (8 per Pack) Item #28803
In stock
$7.99 Pack
5/16" -18 Threaded Inserts (8 per Pack)
5/16" -18 Threaded Inserts (8 per Pack) Item #28811
In stock
$7.99 Pack

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Steel Threaded Inserts - Select size

Item #
88% of 100

These steel threaded inserts can be used anywhere you want the strength and easy assembly of a bolted connection with a wooden joint. Simply bore a hole, drive in the threaded insert, and use a bolt of the appropriate length to secure the adjoining member in place. Perfect for eliminating stripping and pull-out problems in knockdown furniture. See below for individual sizes. Size listed below is the size of the bolt (sold separately) that threads into the insert.


  • Can be installed with screwdriver, threaded insert wrench or threaded insert power drive tool
  • Rugged steel construction
  • Can be used for wood/wood joints, or wood/non-wood joints
  • Brad point drill recommended for drilling pilot hole
  • To install, simply drill a pilot hole slightly narrower than threaded insert body
(1) Pack of Steel Threaded Inserts
More Information
Weight 0.1800
4.4 / 5.0
79 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
Worked very well. Drilled with size of bit per instructions. Used a jam nut on a 1/4-20 bolt to cut the threads. Backed it out, used air to clean out the holes, and dribbled a small amount of CA glue on the threads before reinserting to securely fasten it to the frame. Very quick and clean installation.
User submitted image
User submitted image
User submitted image
July 6, 2019
9 months ago
Woodworking Experience:
Threaded inserts
I have been using these threaded inserts to build baby cribs and beds. Work phenomenally well and allow me securely mount to the head and foot boards to the rails easily!
June 22, 2019
over 4 years ago
Made it so I could take project apart
April 13, 2019
1 year ago
Woodworking Experience:
Great product
Used for crib project
Used for crib project
January 15, 2019
over 5 years ago
Woodworking Experience:
I used these to bolt the legs on my end tables. Highly recommend
October 20, 2018
1 year ago
Woodworking Experience:
Great product
Works as expected.
July 31, 2018
1 year ago
Woodworking Experience:
Thread and hold tighly into wood. Slot drive remains intact.
July 11, 2018
over 3 years ago
Woodworking Experience:
Great item
May 5, 2018
over 3 years ago
Woodworking Experience:
Good Anchor - Easy Install
Perfect for securing a top to a mobile cabinet.
Be sure to get the installer tool. Makes install EASY!
March 5, 2018
over 2 years ago
Woodworking Experience:
Works great. Had to make a jig so I could install them straight. Used to attach the top to a TV component cabinet. Recommend.
February 21, 2018
over 3 years ago
Woodworking Experience:
Start typing your question and we'll check if it was already asked and answered. Learn More
Browse 17 questions Browse 17 questions and 31 answers
Why did you choose this?
Rockler Store
Shane C on Aug 19, 2018
Christopher F on Jul 15, 2018
Shane C on Aug 19, 2018
I need a strong insert to hold, I've tried brass but will not hold. So I choose your steel product. Hope this works. MAGA....
Paul H on Aug 13, 2018
Christopher F on Jul 15, 2018
Finishing up a project
Daniel C on Jul 15, 2018
Brass inserts not beefy enough
Paul T on Jul 9, 2018
need this size inserts
Christopher F on Jun 20, 2018
Hurricane Shutter installation
Michael B on Jun 6, 2018
Need to repair where wood screws have pulled out
Travis R on May 31, 2018
Attaching the top of a platform bed to the base so it doesn't tip over
Benjamin N on May 10, 2018
Needed for project
Larry G on May 4, 2018
easily thread sacrificial wood blanks into track
Richard C on Apr 23, 2018
I am going to try these to attach table tops. Other fasteners don't seem to work too well.
tom g on Apr 22, 2018
Recommended in project plan.
Gary T on Apr 17, 2018
easy for breakdown
james W on Apr 16, 2018
needed for swivel levers
R O on Mar 28, 2018
to install table foot (I hope)
Karl B on Mar 20, 2018
Steel for stronger set up
Dennis H on Mar 19, 2018
I've had very good success with these threaded inserts. A long ago I also got a threaded insert installer from Woodsmith, I believe. I just checked their website, but I no longer found the item. I still have and still use their installer, and combined with these threaded inserts, it's a very sound connection that is easy to install.
Joseph F on Mar 7, 2018
needed it
Libby H on Mar 4, 2018
To make a large wooden legged table portable by making the legs screw in.
George A on Feb 21, 2018
glen d on Jan 26, 2018
To mount leveling feet.
Kirk M on Jan 23, 2018
first time using this method
Dan K on Jan 22, 2018
jig making
Lloyd C on Jan 19, 2018
past use
John M on Jan 19, 2018
to repair a chair arm
James W on Dec 31, 2017
Parts for a plan in Woodworkers Journal
Mitch F on Dec 7, 2017
Make custom cutting board for wife
Phillip M F on Nov 26, 2017
brass not in stock
john m on Nov 14, 2017
Fixing broken table leg.
Philip V on Oct 15, 2017
large table legs
Francis H on Sep 26, 2017
i needed them.
michael o on Sep 1, 2017
To match screw size in door hinge
Dan N on Aug 29, 2017
The size.
Carmelo M on Jul 10, 2017
It is steel and the right size.
Tom V on Jun 3, 2017
Recommended on a YouTube video
Keith T on Jun 2, 2017
they work great for mating machine screws to wood
Keith D on Apr 26, 2017
Special application needed for to attach drawer fronts with no visible handle or pull.
Paul Z on Apr 25, 2017
Never tried inserts before...never had the I do.
JAMES T on Apr 24, 2017
There is no other insert that works for end-grain maple. No one sells this insert but Rockler.
Steven R on Apr 19, 2017
Paul R on Apr 17, 2017
1/4-20 inserts for table legs
glenn b on Apr 9, 2017
To compare with the brass inserts in regard to ease of installation as well as amount of time to install.
Roger L on Apr 4, 2017
using to make adjustable feet and movable portions of a painting easel
Kristopher R on Mar 27, 2017
I am making something that I would like to join with inserts
Michael P on Mar 25, 2017
I need to fasten wood to metal and need a strong joint
galen on Mar 22, 2017
Needed these for a project and after reading the reviews I was sold.
Foyal C on Mar 19, 2017
I stock threaded inserts in my shop of all sizes for future projects. They work wonderfully on projects and jigs.
Dave S on Mar 12, 2017
These are stronger and more durable than regular T-nuts.
Roger F on Mar 4, 2017
same thing
lorne b on Feb 28, 2017
I need a strong insert to hold, I've tried brass but will not hold. So I choose your steel product. Hope this works. MAGA....
Paul H on Aug 13, 2018
Finishing up a project
Daniel C on Jul 15, 2018
What is the OD of the 3/8" insert? Also what is the recommended pilot hole size when installing in hardwood?
Tom L on Mar 16, 2016
BEST ANSWER: From an earlier Rockler order, the tech sheet that came with mine says that for the 3/8"-16, use 1/2" pilot hole in softwood and 9/16" in hardwood. I always do a test in the wood of interest. If properly sized, the wood should not expand noticeably above the surface you insert the insert into. I never had any luck installing them with a screw driver. Use a bolt with a couple of nuts and make sure the insert is perpendicular to the board.
What are the external thread specifications for all three sizes of these steel threaded fasteners? If they are standard threads, using a steel tap or even a bolt to partially "pre-thread" the drilled holes in hardwoods might be helpful.
Rob M on Oct 27, 2015
BEST ANSWER: The external threads are intentionally coarse for better holding in wood and I do not think they are standard threads for which a regular metal working tap would be of assistance.
How long are they?
A shopper on Aug 12, 2015
BEST ANSWER: The 8-32 insert is 3/8 long, and the 1/4-20 and 5/16-18 inserts are 1/2 long, according to the Threaded Insert Technical Data sheet linked above.
what are the outer dimensions for the 3/8-16 insert also how long is the 3/8-16 insert?
Charlie G on Nov 21, 2016
Just saw a video that says the slotted end should go in first as it's there to help cut the threads and not for a slotted screwdriver. Is that true?
A shopper on Jun 13, 2015
Steel Threaded Inserts - Select size
Steel Threaded Inserts - Select size
Threaded Brass Inserts - Select size
Threaded Brass Inserts - Select size
BEST ANSWER: I would say NO! If the slotted end went in first, How do you screw it in? Also, they sale an installation tool that uses the slot. I made my own tool by using a correct size bolt and a lock nut to secure it to the insert. The use a wrench or nut drive to install the insert.
Does the chamber hole go all the way through? I'm thinking of using this as a leveling mechanism and need a threaded cylinder without a bottom.
Dennis K on Aug 5, 2015
BEST ANSWER: Yes. In theory you could even stack them on top of each other to provide more resistance to the pressure applied by leveling if need be. Just drill your hole, insert a matching fastener, and spin both inserts on to fastener shaft. then drive inserts into hole until flush with top of hole
What is the length of the 5/16-18 insert?
Richard S on Aug 17, 2017
BEST ANSWER: That is 1/2" long
I have a footstool whose legs are attached via screwing the legs into threaded inserts in the footstool. Unfortunately, the threaded inserts just keep pulling out of the footstool. (Admittedly, it's a cheaply made footstool, but it has sentimental value for my family.) Any ideas on how to make the threaded inserts more secure? Or, alternative approaches to try for attaching the legs?
csdjj on Jun 2, 2017
BEST ANSWER: Two suggestions:
1. Epoxy the outside thread of the insert into the stool's bottom board.
2. switch to the screw on tee nut style that has 3 screws to secure a plate with the same internal thread. The prong style Tee Nuts will have the same problem as the thread insert unless you can install them on the opposite side of the board in the foot stool.
Screw-On Tee Nuts-Choose size thread
Screw-On Tee Nuts-Choose size thread
Can they be used in exterior application?
Matt H on Oct 7, 2019
BEST ANSWER: These are not stainless so any exposure to moisture will cause them to rust. Depending on the application that could be simple surface rust or it could be more. As to durability, I would say they are fine for inside or out
I need to anchor a machine thread bolt to a wood screw anchor. Do these come with machine thread interior ?
joel m on May 10, 2017
BEST ANSWER: I have used these directly in wood to anchor machine bolts with satisfactory results. See the rockler catalog for internal machine threads available from 8-32 to 5/16-18. if you are going to join to an anchor already in the wood you may want to consider using a rod coupling nut; there is a much longer thread than you would get with the insert, which is intended for a single bolt.

1/4 in.-20 tpi Zinc Rod Coupling Nuts

Everbilt 1/4 in.-20 tpi Zinc Rod Coupling Nuts
what is the I.D. size and thread of 5/16 by 18 insert?
c7sparks on Jan 22, 2020
BEST ANSWER: 5/16 thread
How tall are the 1/4 - 20 inserts?
Thickness of wood inserted in?
Tom H on Jan 13, 2020
BEST ANSWER: I've already used up the supply I have/had, but they were mostly used in 3/4" plywood and 1 x (3/4) stock. I built a shop cabinet that I wanted to be able to knock down. I've also used them to attach bed frames to headboards.
What size hole to drill for 5/16 18 wood insert nut ?
Tom G on Aug 31, 2019
BEST ANSWER: For the 5/16 steel threaded inserts, the correct pilot hole size in soft wood is 29/64". For hard woods drill a 15/32" pilot hole.
I want to fasten two separate wood rods (1inch dia and 36inch length)end to end. (1)Are threaded inserts good for the job. (2) What dimensions of threaded inserts do I need. (3) What other tools do I need?
Pranay M on Feb 6, 2017
BEST ANSWER: You can fasten the 2 rod together, but it will not support very much weight.
Do you sell the bolts that go with each of these Threaded Inserts?
Johnny Boy on Aug 20, 2016
BEST ANSWER: The inserts use standard inside thread sizes. Rockler does carry them in various sizes but so does any hardware store or big box home center. Just order/pick up the length and type that you need.
What is the internal thread pitch for the 8-32 insert? It doesn't say on the listing. I am needing an insert with a 8mm 1.25 pitch.
Ryan V on Jun 8, 2016
BEST ANSWER: 8-32 is a US size meaning a "number 8" at 32 threads per inch. I believe the thread diameter is .16 inch or 5/32 inch.
I need very large inserts. One that will hold 5/8"to 3/4" bolts. I need them to sink into the wood, the bolts that is, at least 4 to 5 inches. Do you have them in the size. If not can you tell me where I can get them?
Gary P on Sep 10, 2017
Prop 65 WarningWARNING: Cancer & Reproductive Harm -

Prop 65 WarningWARNING: Drilling, sawing, sanding or machining wood products can expose you to wood dust, a substance known to the State of California to cause cancer. Avoid inhaling wood dust or use a dust mask or other safeguards for personal protection. For more information go to