Lyman 40011 Black Nitride Stainless Steel 1/2"x28 Threads Compatible w/ SureFire X300U-A Series
The Lyman 40011 is a black nitride stainless steel accessory adapter threaded for 1/2"x28 specifications, engineered for users running SureFire X300U-A tactical lights on their rifles or pistols. If you're building a precision or duty rifle with a modern light setup, this adapter bridges the gap between standard muzzle threads and SureFire's proven X300U-A mounting platform, letting you maximize the efficiency of your existing gear without replacing components that already work.
Built from stainless steel with a black nitride finish, the 40011 delivers the corrosion resistance you need in field conditions while maintaining a professional, low-profile appearance. The nitride coating adds durability against wear and environmental exposure—important if you're running this in wet climates, salt environments, or rough terrain where gear takes a beating.
This is a straightforward, no-frills adapter: solid engineering from a brand with deep roots in shooting sports. Whether you're mounting a light on a primary rifle, a secondary pistol, or swapping setups between guns, having the right thread adapter on hand keeps your workflow smooth and your light secure where it belongs.
Key Features
- 1/2"x28 thread pattern for standard muzzle compatibility
- Black nitride stainless steel construction for corrosion resistance and durability
- Designed for SureFire X300U-A series integration
- Compact, low-profile design
Specifications
| Brand | Lyman |
| Model | 40011 |
| Thread Pattern | 1/2"x28 |
| Material | Stainless Steel |
| Finish | Black Nitride |
| Compatibility | SureFire X300U-A Series |
Frequently Asked Questions
Will this work with my SureFire X300U-A light?
Yes. The Lyman 40011 is designed specifically to interface with SureFire X300U-A series lights on firearms with 1/2"x28 threaded muzzles.
What firearms have 1/2"x28 threads?
1/2"x28 is a common muzzle thread on modern rifles and many tactical-profile pistols, particularly AR-15s and similar carbines. Verify your firearm's thread pitch before ordering to ensure compatibility.
How does the black nitride finish hold up in harsh conditions?
Black nitride is a proven finish in firearms work—it resists corrosion and wear better than bare steel, making it well-suited for field use, wet climates, and regular handling.

