Assembled AR-15 Gas Block and Tube – Let Us Simplify Your Build!
An assembled AR-15 gas block and tube cuts out one of the most inconvenient parts of upgrading your barrel or handguard. Driving in the gas tube roll pin can be a pain without punches or a jig, so we’re making things easier for you! Let AT3 take care of pinning your gas block and tube, so all you need to do is slide on your tube, crank down the set screws, and get on with your day.
How does this work?
Use the dropdown menus to choose your size of gas block and gas tube length. We’ll assemble them with a pinned gas tube and ship it to you!
Not sure what size you need? Check out the FAQ at the bottom of this page.
About the AT3 Low Profile Steel Gas Blocks:
- 4 sizes available: .625″, .75″, .825″, and .936 (.75″ is the most common size, but always measure the barrel if you aren’t sure!)
- Low profile design, perfect with all free float handguards
- Premium steel construction (better than aluminum for withstanding extreme temperatures)
- Secured using 2 set screws
- Backed by the AT3 Lifetime Warranty
About the AT3 Gas Tubes:
Premium stainless steel gas tubes, available in 4 lengths. Backed by a lifetime warranty.
Not sure what size you need? Measure the distance from the barrel shoulder to the gas port on your barrel and compare it to the chart below. (Carbine is the most common length).
Distance to port:
- Pistol = 4 inches
- Carbine = 7 inches
- Mid = 9 inches
- Rifle = 12 inches
More Details:
AT3 Gas Block Specifications:
- Material: 4150 Steel, Black Finish
- Length: 1″
- Height: Sits 3/8″ off of the barrel (fits under all free float handguards)
- Weight: 1.5-1.8oz depending on size
AT3 Gas Tube Specifications:
- Material: Stainless Steel
- Finish: Natural
Total Tube Length:
- Pistol: 6 3/4″
- Carbine: 9 3/4″
- Mid-length: 11 3/4″
- Rifle: 15 1/4″
Frequently asked questions:
Q: How can I tell what size of gas block I need?
A: The gas block size is based on the outside diameter of your barrel. The most common size is .75″ (this is the military standard). If you aren’t sure – use calipers to measure the diameter of the barrel, in the area where the gas block sits. Or alternatively, you can try looking up the make and model of your rifle online for more details.
Q: How do I know if this gas block will fit under my handguard?
A: Our micro gas blocks are as small as you will find on the market. They are guaranteed to work with our AT3 handguards, and they are compatible with all the other handguards out there!
Q: How do I know what size of the gas tube I need?
A: Measure the distance from the barrel shoulder to the gas port on your barrel and compare it to the list below. (Carbine is the most common length).
Distance to port:
- Pistol = 4 inches
- Carbine = 7 inches
- Mid = 9 inches
- Rifle = 12 inches
Products available on this page:
- AT3 Tactical Assembled Gas Block and Tube Combo for AR-15 - Gas Block Size: .750" Micro Gas Block, Gas Tube Length: Mid-Length | SKU: GB-75-GT-09-ASM
- AT3 Tactical Assembled Gas Block and Tube Combo for AR-15 - Gas Block Size: .750" Micro Gas Block, Gas Tube Length: Carbine | SKU: GB-75-GT-07-ASM
- AT3 Tactical Assembled Gas Block and Tube Combo for AR-15 - Gas Block Size: .750" Micro Gas Block, Gas Tube Length: Pistol | SKU: GB-75-GT-04-ASM
- AT3 Tactical Assembled Gas Block and Tube Combo for AR-15 - Gas Block Size: .625" Micro Gas Block, Gas Tube Length: Mid-Length | SKU: GB-625-GT-09-ASM
- AT3 Tactical Assembled Gas Block and Tube Combo for AR-15 - Gas Block Size: .625" Micro Gas Block, Gas Tube Length: Carbine | SKU: GB-625-GT-07-ASM
- AT3 Tactical Assembled Gas Block and Tube Combo for AR-15 - Gas Block Size: .625" Micro Gas Block, Gas Tube Length: Pistol | SKU: GB-625-GT-04-ASM
- AT3 Tactical Assembled Gas Block and Tube Combo for AR-15 - Gas Block Size: .625" Micro Gas Block, Gas Tube Length: Rifle | SKU: GB-625-GT-12-ASM
- AT3 Tactical Assembled Gas Block and Tube Combo for AR-15 - Gas Block Size: .750" Micro Gas Block, Gas Tube Length: Rifle | SKU: GB-75-GT-12-ASM
- AT3 Tactical Assembled Gas Block and Tube Combo for AR-15 - Gas Block Size: .875" Micro Gas Block, Gas Tube Length: Pistol | SKU: GB-875-GT-04-ASM
- AT3 Tactical Assembled Gas Block and Tube Combo for AR-15 - Gas Block Size: .875" Micro Gas Block, Gas Tube Length: Carbine | SKU: GB-875-GT-07-ASM
- AT3 Tactical Assembled Gas Block and Tube Combo for AR-15 - Gas Block Size: .875" Micro Gas Block, Gas Tube Length: Mid-Length | SKU: GB-875-GT-09-ASM
- AT3 Tactical Assembled Gas Block and Tube Combo for AR-15 - Gas Block Size: .875" Micro Gas Block, Gas Tube Length: Rifle | SKU: GB-875-GT-12-ASM
- AT3 Tactical Assembled Gas Block and Tube Combo for AR-15 - Gas Block Size: .936" Micro Gas Block, Gas Tube Length: Pistol | SKU: GB-936-GT-04-ASM
- AT3 Tactical Assembled Gas Block and Tube Combo for AR-15 - Gas Block Size: .936" Micro Gas Block, Gas Tube Length: Carbine | SKU: GB-936-GT-07-ASM
- AT3 Tactical Assembled Gas Block and Tube Combo for AR-15 - Gas Block Size: .936" Micro Gas Block, Gas Tube Length: Mid-Length | SKU: GB-936-GT-09-ASM
- AT3 Tactical Assembled Gas Block and Tube Combo for AR-15 - Gas Block Size: .936" Micro Gas Block, Gas Tube Length: Rifle | SKU: GB-936-GT-12-ASM
