STI Series

Product Details

Square Tubing Inserts

Square tubing inserts, otherwise known as STI Series products, are finishing plugs that companies can use in a variety of square applications. These durable plastic plugs for square tubing provide a clean, protective finish and simplify assembly for manufacturers. External tapered ribs ensure a secure fit in a wide range of tubing gauges, and a sleek outer appearance ensures a flawless seam when installed.

They also resist vibration and maintain retention under load, reducing onsite maintenance. With square tubing plugs, you can spruce up the style of older furniture pieces, complete unfinished installation work, and keep unsightly interior components hidden from view.

Installers appreciate quick press-fit installation that saves time on production lines. The plugs seal openings to block dirt and moisture, extending service life. For added functionality, our threaded inserts for square tubing accept fasteners and allow secure attachments.

Learn more about our versatile STI Series products below.

Technical Specifications

Color: Black
Material: Low Density Polyethylene
LDPE service temperature: 150°F (66°C)
Some parts are also available with domed and/or other types of top profiles
Additional sizes available (consult factory for details)
RoHS Compliant

Part No. Color To Fit Tube Size To Fit Tube Gauge Tube Wall Thickness Product Options

Part No. STI-1/2 16-18

Color

Black

To Fit Tube Size

1/2"

To Fit Tube Gauge

16-18

Tube Wall Thickness

.065 -.049

Part No. STI-5/8 14-20

Color

Black

To Fit Tube Size

5/8"

To Fit Tube Gauge

14-20

Tube Wall Thickness

.083-.035

Part No. STI-3/4 14-20

Color

Black

To Fit Tube Size

3/4"

To Fit Tube Gauge

14-20

Tube Wall Thickness

.083-.035

Part No. STI-7/8 14-20

Color

Black

To Fit Tube Size

7/8"

To Fit Tube Gauge

14-20

Tube Wall Thickness

.083-.035

Part No. STI-1 10-14

Color

Black

To Fit Tube Size

To Fit Tube Gauge

10-14

Tube Wall Thickness

.134-.083

Part No. STI-1 14-20

Color

Black

To Fit Tube Size

To Fit Tube Gauge

14-20

Tube Wall Thickness

.083-.035

Part No. STI-1-1/8 14-20

Color

Black

To Fit Tube Size

1 1/8"

To Fit Tube Gauge

14-20

Tube Wall Thickness

.083-.035

Part No. STI-1-1/4 10-14

Color

Black

To Fit Tube Size

1 1/4"

To Fit Tube Gauge

10-14

Tube Wall Thickness

.134-.083

Part No. STI-1-1/4 14-20

Color

Black

To Fit Tube Size

1 1/4"

To Fit Tube Gauge

14-20

Tube Wall Thickness

.083-.035

Part No. STI-1-3/8 14-20

Color

Black

To Fit Tube Size

1 3/8"

To Fit Tube Gauge

14-20

Tube Wall Thickness

.083-.035

Part No. STI-1-1/2 10-14

Color

Black

To Fit Tube Size

1 1/2"

To Fit Tube Gauge

10-14

Tube Wall Thickness

.134-.083

Part No. STI-1-1/2 14-20

Color

Black

To Fit Tube Size

1 1/2"

To Fit Tube Gauge

14-20

Tube Wall Thickness

.083-.035

Part No. STI-1-3/4 10-14

Color

Black

To Fit Tube Size

1 3/4"

To Fit Tube Gauge

10-14

Tube Wall Thickness

.134-.083

Part No. STI-2 10-14

Color

Black

To Fit Tube Size

To Fit Tube Gauge

10-14

Tube Wall Thickness

.134-.083

Part No. STI-2 14-20

Color

Black

To Fit Tube Size

To Fit Tube Gauge

14-20

Tube Wall Thickness

.083-.035

Part No. STI-2-3/8 6-10

Color

Black

To Fit Tube Size

2 3/8"

To Fit Tube Gauge

6-10

Tube Wall Thickness

.203-.134

Part No. STI-2-1/2 10-14

Color

Black

To Fit Tube Size

2 1/2"

To Fit Tube Gauge

10-14

Tube Wall Thickness

.134-.083

Part No. STI-2-1/2 14-20

Color

Black

To Fit Tube Size

2 1/2"

To Fit Tube Gauge

14-20

Tube Wall Thickness

.083-.035

Part No. STI-3 10-14

Color

Black

To Fit Tube Size

To Fit Tube Gauge

10-14

Tube Wall Thickness

.134-.083

Part No. STI-3-1/2 6-11

Color

Black

To Fit Tube Size

3 1/2"

To Fit Tube Gauge

6-11

Tube Wall Thickness

.194-.120

Part No. STI-3.63 7-11

Color

To Fit Tube Size

3.63"

To Fit Tube Gauge

7-11

Tube Wall Thickness

.179-.120

Part No. STI-4 7-11

Color

Black

To Fit Tube Size

To Fit Tube Gauge

7-11

Tube Wall Thickness

.179-.120

Part No. STI-5 7-11

Color

Black

To Fit Tube Size

To Fit Tube Gauge

7-11

Tube Wall Thickness

.179-.120

Part No. STI-6 7-11

Color

Black

To Fit Tube Size

To Fit Tube Gauge

7-11

Tube Wall Thickness

.179-.120

Part No. STI-40 MM 14-20

Color

Black

To Fit Tube Size

40 mm

To Fit Tube Gauge

14-20

Tube Wall Thickness

2.0 -1.0 mm

Part No. STI-50 MM 11-20

Color

Black

To Fit Tube Size

50 mm

To Fit Tube Gauge

11-20

Tube Wall Thickness

3.2-1.0 mm

Part No. STI-60 MM 6-11

Color

Black

To Fit Tube Size

60 mm

To Fit Tube Gauge

6-11

Tube Wall Thickness

5.0-3.0 mm

Part No. STI-80 MM 5-13

Color

Black

To Fit Tube Size

80 mm

To Fit Tube Gauge

5-13

Tube Wall Thickness

2.5-5.6 mm

Configure & Order

Product Details

Square Tubing Inserts

Technical Specifications

Part No. STI-1/2 16-18

Part No. STI-5/8 14-20

Part No. STI-3/4 14-20

Part No. STI-7/8 14-20

Part No. STI-1 10-14

Part No. STI-1 14-20

Part No. STI-1-1/8 14-20

Part No. STI-1-1/4 10-14

Part No. STI-1-1/4 14-20

Part No. STI-1-3/8 14-20

Part No. STI-1-1/2 10-14

Part No. STI-1-1/2 14-20

Part No. STI-1-3/4 10-14

Part No. STI-2 10-14

Part No. STI-2 14-20

Part No. STI-2-3/8 6-10

Part No. STI-2-1/2 10-14

Part No. STI-2-1/2 14-20

Part No. STI-3 10-14

Part No. STI-3-1/2 6-11

Part No. STI-3.63 7-11

Part No. STI-4 7-11

Part No. STI-5 7-11

Part No. STI-6 7-11

Part No. STI-40 MM 14-20

Part No. STI-50 MM 11-20

Part No. STI-60 MM 6-11

Part No. STI-80 MM 5-13

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