2-1/2″ OD, 2-1/4″ ID Fiberglass Round Tube


Pultruded Fiberglass Tube

Nominal Dimensions
Outer Diameter: 2.5″
Inner Diameter: 2.25″
Wall Thickness: 0.125″
Color: Gray, Black

Length: Choose the length of the tube

2-1/2″ OD, 2-1/4″ ID, Fiberglass Round Tube, Gray

Our 2-1/2″ OD, 2-1/4″ ID, fiberglass tube is made by the pultrusion process. Fiberglass (random directional) mat, pulled via hydraulics through a bath of resin and pigment. Heated and cured. Our stock lengths are the perfect sizes to ship via standard parcel carriers like FedEx and Post. 8 foot long lengths fit under the oversize 3 shipping mark. Oversize 3 goods (anything over 96.02 inches) will all ship at freight rates which start at $120 and rise from there making our lengths of tube perfect for prototyping, hobbyist, etc…

This listing contains all of the product offerings for the 2-1/2″ OD, 2-1/4″ ID Round Tube including: RT-212-05G, RT-212-2G, RT-212-4G, RT-212-8G, RT-212-05B, RT-212-2B, RT-212-4B, and RT-212-8B

Round Tube Typical Properties

Round Tube Properties

MGS Fiberglass Sizes that sleeve 2-1/2″ OD, 2-1/4″ ID, Round Hollow Tube:

RT-212 2.5 inch OD Round Hollow Tube sleeving RT-214 2.25 inch OD Round Hollow Tube diagram 800x800 - Max-Gain Systems, Inc.

2.25 inch OD Round Hollow Tube fits inside our 2.50 inch OD Round Hollow Tube (full length sleevable)

Attachments that fit-on, clamp-on, couple, etc…

MC-250 GR-225 RT-214 RT-212 diagram 300x300 - Max-Gain Systems, Inc.The MC-250 quik-clamp telescoping tube clamp fits on the end of the 2.5 inch OD Round Tube and allows the telescoping of the 2.25 inch OD Round Tube.

Vinyl End Caps 800x800 - Max-Gain Systems, Inc.The VEC-212 Vinyl End Cap fits on the end of the 2.5 inch OD Round Tube.

Mounts to the ground, walls, vehicles, etc…

Ground Base Mast Mount Kit fully assembled - Max-Gain Systems, Inc.The 2.5 inch ID Ground Mount can accept 2.5 inch OD Round Tube.

Truck Drive-On Mast Mount - Max-Gain Systems, Inc.The 2.5 inch ID Drive-On Mount can accept 2.5 inch OD Round Tube.

Heavy Duty mast raised on a hitch mount for a quick mobile deployment system 800The 2.5 inch ID Hitch Mount will accept 2.5 inch OD Round Tube and can be used on a vehicle hitch.

Tripod Mast Mount 800x800 - Max-Gain Systems IncThe 2.5 inch ID Tripod Mount will accept 2.5 in OD tube and provide a great base for a vertical structure

M-S212 2.5 inch Support Tube for Heavy Duty (HD) series masts and Heavy Duty Extend (EXT) series mastsThe 2.5 inch ID Bumper/Base Mount will accept 2.5 in OD tube and can be used to attach to a car bumper, trailer, concrete, etc…

Mast Wall Mount Bracket Fits Round Tube and Rod from 1.75 inch OD thru 2.5 inch OD M-W212L 800x800 - Max-Gain Systems, Inc.The 2.5 inch ID Wall Mount can be used to attach 2.5 inch OD Round Tube to a wall.

Round Tube Sleeving and Reinforcement

Sleeving and Reinforcement Guide Round Tube and Rod 800x800 - Max-Gain Systems, Inc.

Round Tube Sleeving Sample Pack

RT-SPL 250x250 Fiberglass Round Hollow Tube Sleeving Sample Pack - Max-Gain Systems, Inc.

This Round Tube is available in a Round Sleeving Tube Sample Pack for easier product evaluation. Easily acquire a 6 inch or 2 foot long piece of each size of Round Fiberglass Tube.

Please note: The sleeving and reinforcement guide below is for Max-Gain Systems’ proprietary line of tube and rod only. All sizes are “nominal” and allow a few thousandths for sleeving purposes.

These same stated sizes of tube and rod from other manufacturers probably will NOT mate with our line!

Round Tube
Tubing Size
Accepted Inside Sizes
Accepted Outside Sizes
no direct sizes
no direct sizes
no direct sizes
no direct sizes
no direct sizes

Fiberglass Information and Resources


Fiberglass Joining 250x250 - Max-Gain Systems, Inc.

Joining and connecting tubes and rods together through many different methods. Find out which method works for you!


FG Circular Saw Raw 250x250 - Max-Gain Systems, Inc.

Information on cutting and drilling fiberglass tube and rods. Including which tools work best!


Bonding & Adhesives 250x250 - Max-Gain Systems, Inc.

Information on bonding fiberglass shapes together thru chemical adhesion. Including what NOT to use!


Painting Fiberglass with Rustoleum Spray 250x250 - Max-Gain Systems, Inc.

Information on painting fiberglass tube and rods. Best practices and tips on how to make it less visible.


Fiberglass Quad Spreaders and other sleeved fiberglass 250x250 - Max-Gain Systems, Inc.

We offer telescoping, Quad Spreaders with usable lengths up to a total of 26 feet! Telescoping Quad Spreaders are discounted from individual piece prices! See our Quad Spreader Information Sheet for details.


Quantity discounts on fiberglass preformed shapes 250x250 - Max-Gain Systems, Inc.

Buying ten or more quantity of one size of fiberglass qualifies for a 10% quantity discount on that item. Fifty or more, of one size, qualifies for 15%, and one hundred or more 20%.


Manufacturing pultruded fiberglass tube and rod 250x250 - Max-Gain Systems, Inc.

If you are a reseller or manufacturer, you may qualify for our factory-direct, wholesale/O.E.M. pricing! SUBSTANTIAL savings are possible with increasing volume, and our customer service is unsurpassed. Email us for quantity pricing.


Drilling3 grayscale 250x250 - Max-Gain Systems, Inc.

Available free by telephone. For almost unlimited life, we highly recommend that any fiberglass – even ours which is UV-stabilized – be painted. A sprayed primer coat and flat-black top coat, works best. (See our Max-Tips Info Sheet for details.)

About Max-Gain Systems, Inc.

Max-Gain Systems, Inc. carries a full line of in-series, between series, right angle, T-shaped, quick connect, handie-talkie (BLACK), pigtails (coaxial jumpers), etc… RF adapters. Our RF adapter lines are constantly expanding. We keep our RF connector and adapter lines in stock. We ship both retail and wholesale quantities. To become a dealer / wholesale user, contact us with your potential usage.

Max-Gain Systems, Inc. is the number one supplier of fiberglass round hollow tube, square tube and round solid rod to the antenna manufacturing industry. We produce millions of feet a year for hundreds of different industries. Including but not limited to:  marine / boating, aeronautical, agriculture, construction, emergency services, etc….  We have the unique ability to sell one piece or even a semi-truck full. Feel free to prototype using our fiberglass tube and rod then contact us for a quote on a production run. At production run quantities we can cut to your desired lengths at no additional charge. We can also perform several different fabrications (example: drilling holes in precise locations along a tube) to ensure your delivered material is ready for assembly. We have several accessory items designed for our fiberglass including but not limited to: couplers, telescoping clamps, ferrules, etc…

RT-212-05G, RT-212-2G, RT-212-4G, RT-212-8G, RT-212-05B, RT-212-2B, RT-212-4B, RT-212-8B

Additional information

Shipping Weight N/A
Shipping Dimensions N/A
Outer Diameter

2-1/2'' OD (2.5 in) | 63.5 mm

Inner Diameter

2-1/4" ID (2.25 in) | 57.15 mm

Weight per Linear Foot (lb/ft)


Wall Thickness

1/8" Wall


6 in, 23.25 in, 46.5 in, 93 in


Black, Gray


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