The Guntec USA Low-Profile .625 Gas Block (brand part no. GT625SS) is a steel gas block built for AR-15 rifles running a .625-inch barrel journal. Machined with a low-profile design, it tucks cleanly under free-float handguards for a cleaner, snag-free rifle profile while still metering gas reliably to the bolt carrier group. Made in the USA from durable steel with a matte finish, it’s a straightforward upgrade for builders replacing a worn factory gas block or finishing out a custom upper. A roll pin ships with the block for a secure, no-guesswork installation.

Key Specifications

• The block is sized for a .625-inch diameter barrel journal, matching common AR-15 barrel contours at the gas port.
• Its low-profile design keeps the block compact enough to sit under most free-float handguards.
• It’s machined from steel for long-term durability under repeated heat cycling at the gas port.
• A matte black finish resists wear and matches most factory AR-15 finishes.
• A roll pin is included for securing the block to the barrel during installation.
• The block is made in the USA, built to standard AR-15 specifications.

Frequently Asked Questions

What barrel diameter does this gas block fit? It’s sized for a .625-inch diameter barrel journal, a common AR-15 gas block seat.

Will it fit under a free-float handguard? Yes, its low-profile design is built to clear most free-float AR-15 handguards.

Does it include mounting hardware? Yes, a roll pin is included for installation.

Buy the Guntec USA Low-Profile .625 Gas Block

Finish your AR-15 build or replace a tired factory gas block with the Guntec USA Low-Profile .625 Gas Block. Shop the full lineup of Guntec USA gun accessories and parts and get fast shipping from our Lubbock, Texas gun shop.