Metal Threaded Inserts
Metal threaded inserts from Carpin serve two purposes: enclosing the end of a round or square tube; and providing a female receptacle that accepts the threaded stem of glides and casters.
The primary function of a metal threaded insert is to cap off the end of a vertical leg of a table, desk, shelving, or POS display, and to allow an adjustable glide and/or caster with threaded stem to be screwed in. In this configuration, the threaded insert adds strength and functionality to the tubular leg.
All Carpin metal threaded inserts are made of the highest quality steel components. The portion that holds the metal threaded insert securely in the tube is the clip or star washer. Made of high carbon steel that is heat treated for added strength and rigidity, the star washer/clip features a unique shape and geometry that allows for easy insertion and optimum retention. As the threaded insert gets inserted into the tube, the star washer/clip flexes normally to bend in the direction of entry. The edges of the clip then bite into the ID of the tubing, offering rigid support that preventing the clip from being removed.
The end portion of the metal threaded insert is zinc plated steel and hardened for added strength. The two components of the threaded metal insert are fastened together with a steel nut that is wider in diameter than the components, creating an exceptionally strong connection. Several types of metal threaded insert are available, including versions with steel spacers and multiple star washers for added stability and holding power.
Shown below are some common configurations:
Round Metal Threaded Inserts (Series 104) • Square Metal Threaded Inserts with Round Clip (Series 104) Square Metal Threaded Inserts (Series 103 & 105) • Heavy Duty Threaded Metal Inserts (Series 106)
Heavy Duty Threaded Metal Inserts/2 clips (Series 106)
Round Metal Threaded Inserts
Series 104
Series 104 round metal threaded adapters can accommodate round tubing ranging from 3/4” to 1-1/4” (OD) and typically, 16-18 gauge (GA) wall thicknesses.
Metal threaded insert for 3/4" round tubing, 1/4-20, 16-18 ga
Metal threaded insert for 3/4” round tubing, 5/16-18, 16-18 ga
Metal threaded insert for 7/8” round tubing, 1/4-20, 14 ga
Metal threaded insert for 7/8” round tubing, 1/4-20, 16-18 ga
Metal threaded insert for 7/8” round tubing, 5/16-18, 14 ga
Metal threaded insert for 7/8” round tubing, 5/16-18, 16-18 ga
Metal threaded insert for 1” round tubing, 1/4-20, 14 ga
Metal threaded insert for 1” round tubing, 1/4-20, 16-18 ga
Metal threaded insert for 1” round tubing, 5/16-18, 14 ga
Metal threaded insert for 1” round tubing, 5/16-18, 16-18 ga
Metal threaded insert for 1” round tubing, 3/8-16, 14 ga
Metal threaded insert for 1” round tubing, 3/8-16, 16-18 ga
Metal threaded insert for 1-1/8” round tubing, 1/4-20, 16-18 ga
Metal threaded insert for 1-1/8” round tubing, 5/16-18, 16-18 ga
Metal threaded insert for 1-1/8” round tubing, 3/8-16, 16-18 ga
Metal threaded insert for 1-1/4” round tubing, 1/4-20, 16-18 ga
Metal threaded insert for 1-1/4” round tubing, 5/16-18, 16-18 ga
Metal threaded insert for 1-1/4” round tubing, 3/8-16, 16-18 ga
Other sizes are available upon request
tube (A)
3/4"
3/4"
7/8"
7/8"
7/8"
7/8"
1"
1"
1"
1"
1"
1"
1-1/8"
1-1/8"
1-1/8"
1-1/4"
1-1/4"
1-1/4"
thread (T)
1/4-20
5/16-18
1/4-20
1/4-20
5/16-18
5/16-18
1/4-20
1/4-20
5/16-18
5/16-18
3/8-16
3/8-16
1/4-20
5/16-18
3/8-16
1/4-20
5/16-18
3/8-16
16-18 ga
16-18 ga
14 ga
16-18 ga
14 ga
16-18 ga
14 ga
16-18 ga
14 ga
16-18 ga
14 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
tube wall
thickness
back to top
Square Metal Threaded Inserts with Round Clip
Series 104
Series 104 metal threaded adapters can accommodate square (SQ) tubing ranging from 7/8” to 1” (OD) and 16-18 gauge (GA) wall thicknesses. The round clip is more economical than a square shaped clip and provides adequate holding power in most applications.
Metal threaded insert for 3/4” square tubing, 1/4-20, 16-18 ga
Metal threaded insert for 3/4” square tubing, 5/16-18, 16-18 ga
Metal threaded insert for 7/8” square tubing, 1/4-20, 16-18 ga
Metal threaded insert for 7/8” square tubing, 5/16-18, 16-18 ga
Metal threaded insert for 1” square tubing, 1/4-20, 14 ga
Metal threaded insert for 1” square tubing, 1/4-20, 16-18 ga
Metal threaded insert for 1” square tubing, 5/16-18, 14 ga
Metal threaded insert for 1” square tubing, 5/16-18, 16-18 ga
Metal threaded insert for 1” square tubing, 3/8-16, 14 ga
Metal threaded insert for 1” square tubing, 3/8-16, 16-18 ga
Metal threaded insert for 1-1/8” square tubing, 1/4-20, 16-18 ga
Metal threaded insert for 1-1/8” square tubing, 5/16-18, 16-18 ga
Metal threaded insert for 1-1/8” square tubing, 3/8-16, 16-18 ga
Metal threaded insert for 1-1/4” square tubing, 1/4-20, 16-18 ga
Metal threaded insert for 1-1/4” square tubing, 5/16-18, 16-18 ga
Metal threaded insert for 1-1/4” square tubing, 3/8-16, 16-18 ga
Other sizes are available upon request
tube (A)
3/4"
3/4"
7/8"
7/8"
1"
1"
1"
1"
1"
1"
1-1/8"
1-1/8"
1-1/8"
1-1/4"
1-1/4"
1-1/4"
thread (T)
1/4-20
5/16-18
1/4-20
5/16-18
1/4-20
1/4-20
5/16-18
5/16-18
3/8-16
3/8-16
1/4-20
5/16-18
3/8-16
1/4-20
5/16-18
3/8-16
16-18 ga
16-18 ga
16-18 ga
16-18 ga
14 ga
16-18 ga
14 ga
16-18 ga
14 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
tube wall
thickness
back to top
Square Metal Threaded Inserts
Series 103 and 105
Series 103 and 105 square metal threaded adapters can accommodate square (SQ) tubing ranging from 7/8” to 1” (OD) and 16-18 gauge (GA) wall thicknesses. These specially configured square shaped clips allow for easier installation since the square clip orients the plate with the OD of the tube.
Metal threaded insert with square clip for 7/8” square tubing, 1/4-20, 16-18 ga
Metal threaded insert with square clip for 7/8” square tubing, 5/16-18, 16-18 ga
Metal threaded insert with square clip for 1” square tubing, 1/4-20, 14 ga
Metal threaded insert with square clip for 1” square tubing, 1/4-20, 16-18 ga
Metal threaded insert with square clip for 1” square tubing, 5/16-18, 14 ga
Metal threaded insert with square clip for 1” square tubing, 5/16-18, 16-18 ga
Metal threaded insert with square clip for 1” square tubing, 3/8-16, 14 ga
Metal threaded insert with square clip for 1” square tubing, 3/8-16, 16-18 ga
Other sizes are available upon request
tube (A)
7/8"
7/8"
1"
1"
1"
1"
1"
1"
thread (T)
1/4-20
5/16-18
1/4-20
1/4-20
5/16-18
5/16-18
3/8-16
3/8-16
16-18 ga
16-18 ga
14 ga
16-18 ga
14 ga
16-18 ga
14 ga
16-18 ga
tube wall
thickness
Heavy Duty Metal Threaded Inserts (round or square)
Series 106
Series 106 heavy duty metal threaded adapters are more ruggedly designed for added durability and improved lateral stability. Series 106 heavy duty metal threaded adapters can accommodate both round or square tubing ranging from 1” to 2” (OD) and a variety of wall thicknesses. Compared to Series 104 metal threaded inserts, Series 106 products extend the clip farther into the tube for increased stability, and the construction of the nut allows the threaded insert to carry a greater load, which helps prevent nut failure.
Metal threaded insert for 1” round or square tubing, 5/16-18, 14 ga
Metal threaded insert for 1” round or square tubing, 5/16-18, 16-18 ga
Metal threaded insert for 1” round or square tubing, 3/8-16, 14 ga
Metal threaded insert for 1” round or square tubing, 3/8-16, 16-18 ga
Metal threaded insert for 1-1/8” round or square tubing, 5/16-18, 16-18 ga
Metal threaded insert for 1-1/8” round or square tubing, 3/8-16, 16-18 ga
Metal threaded insert for 1-1/4” round or square tubing, 5/16-18, 16-18 ga
Metal threaded insert for 1-1/4” round or square tubing, 3/8-16, 16-18 ga
Metal threaded insert for 1-1/2” round or square tubing, 5/16-18, 16-18 ga
Metal threaded insert for 1-1/2” round or square tubing, 3/8-16, 16-18 ga
Metal threaded insert for 1-3/4” round or square tubing, 5/16-18, 16-18 ga
Metal threaded insert for 1-3/4” round or square tubing, 3/8-16, 16-18 ga
Metal threaded insert for 2” round or square tubing, 5/16-18, 16-18 ga
Metal threaded insert for 2” round or square tubing, 3/8-16, 16-18 ga
Other sizes are available upon request
tube (A)
1"
1"
1"
1"
1-1/8"
1-1/8"
1-1/4"
1-1/4"
1-1/2"
1-1/2"
1-3/4"
1-3/4"
2"
2"
thread (T)
5/16-18
5/16-18
3/8-16
3/8-16
5/16-18
3/8-16
5/16-18
3/8-16
5/16-18
3/8-16
5/16-18
3/8-16
5/16-18
3/8-16
14 ga
16-18 ga
14 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
tube wall
thickness
Heavy Duty Metal Threaded Inserts with 2 Clips
Series 106
Metal threaded inserts can also be made with two (2) clips to provide added holding power and improved lateral stability. This heavy duty design is particularly beneficial when a caster is used in conjunction with the threaded insert, as the caster may experience significant lateral forces under heavy loads and when traveling over raised obstacles or thresholds. The use of 2 clips may require additional insertion force into the tube, but the clips are extremely resilient once installed. Metal threaded inserts with 2 clips are constructed differently from other versions, with the two clips separated by one or more spacers.
Metal threaded insert for 3/4” round or square tubing, 1/4-20, 16-18 ga
Metal threaded insert for 3/4” round or square tubing, 5/16-18, 16-18 ga
Metal threaded insert for 7/8” round or square tubing, 1/4-20, 16-18 ga
Metal threaded insert for 7/8” round or square tubing, 5/16-18, 16-18 ga
Metal threaded insert for 7/8” round or square tubing, 3/8-16, 16-18 ga
Metal threaded insert for 1” round or square tubing, 1/4-20, 16-18 ga
Metal threaded insert for 1” round or square tubing, 5/16-18, 16-18 ga
Metal threaded insert for 1” round or square tubing, 3/8-16, 16-18 ga
Metal threaded insert for 1-1/8” round or square tubing, 1/4-20, 16-18 ga
Metal threaded insert for 1-1/8” round or square tubing, 5/16-18, 16-18 ga
Metal threaded insert for 1-1/8” round or square tubing, 3/8-16, 16-18 ga
Metal threaded insert for 1-1/4” round or square tubing, 1/4-20, 16-18 ga
Metal threaded insert for 1-1/4” round or square tubing, 5/16-18, 16-18 ga
Metal threaded insert for 1-1/4” round or square tubing, 3/8-16, 16-18 ga
Metal threaded insert for 1-1/2” round or square tubing, 1/4-20, 16-18 ga
Metal threaded insert for 1-1/2” round or square tubing, 5/16-18, 16-18 ga
Metal threaded insert for 1-1/2” round or square tubing, 3/8-16, 16-18 ga
Metal threaded insert for 1-3/4” round or square tubing, 1/4-20, 16-18 ga
Metal threaded insert for 1-3/4” round or square tubing, 5/16-18, 16-18 ga
Metal threaded insert for 1-3/4” round or square tubing, 3/8-16, 16-18 ga
Metal threaded insert for 2” round or square tubing, 1/4-20, 16-18 ga
Metal threaded insert for 2” round or square tubing, 5/16-18, 16-18 ga
Metal threaded insert for 2” round or square tubing, 3/8-16, 16-18 ga
Other sizes are available upon request
tube (A)
3/4"
3/4"
7/8"
7/8"
7/8"
1"
1"
1"
1-1/8"
1-1/8"
1-1/8"
1-1/4"
1-1/4"
1-1/4"
1-1/2"
1-1/2"
1-1/2"
1-3/4"
1-3/4"
1-3/4"
2"
2"
2"
thread (T)
1/4-20
5/16-18
1/4-20
5/16-18
3/8-16
1/4-20
5/16-18
3/8-16
1/4-20
5/16-18
3/8-16
1/4-20
5/16-18
3/8-16
1/4-20
5/16-18
3/8-16
1/4-20
5/16-18
3/8-16
1/4-20
5/16-18
3/8-16
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
16-18 ga
tube wall
thickness
click to view larger image
back to top
back to top
Heavy Duty Metal Threaded Inserts with 4 Clips
Series 106
Under extreme loads and lateral forces, sometimes a 4-clip solution is required. The 4-clip metal threaded insert simply extends the benefits of the 2-clip solution with more clips being added to offer more holding power within the tube. To accommodate the added clips, the threaded insert is designed to be taller and extends deeper into the tube for even greater lateral support. Please inquire about the various 4-clip metal threaded inserts that are available.
In addition to the standard product configurations shown above, Carpin can customize a solution to meet your specific requirements. Please contact us today to learn more.
Related products:
Tube nut
Threaded insert
Threaded tube insert
Threaded adapters