Fasteners in firearms—from handguns to rifles—are engineered precision components that ensure reliability, structural integrity, and consistent performance under recoil, environmental exposure, and high-frequency use. Every screw or bolt in a firearm plays its part in safety and accuracy.
1. Structural Integrity Under Recoil
Fasteners secure the frame, barrel, slide, and optics assembly of a firearm, and must resist the forces generated during firing, including recoil impulse and heat. Premium fasteners are often made from high-strength alloy steel or stainless steel to withstand cyclic stress and maintain joint stability under live fire conditions.
2. Precision Torque Application
For precision firearms—like sniper rifles or duty pistols—proper torque ensures component alignment and accuracy. Optics mounts, trigger groups, and barrel assemblies require calibrated torque to avoid misalignment and ensure repeatable performance. Mis-torqued fasteners can result in accuracy degradation or component failure.
3. Corrosion Resistance and Environmental Durability
Firearms are exposed to moisture, sweat, dust, and high temperatures. To avoid corrosion, fasteners are made from stainless steel or coated alloy steel using finishes like black oxide, cadmium, zinc-nickel, or passivation. These treatments protect integrity without affecting strength or fit.
4. Thread Standards and Compatibility
Firearm screws typically use Unified Thread Standard (UNC/UNF) sizes such as #8-32 or 10-24, with some systems adopting metric M4 or M5 screws. Drive types range from hex and Torx to slotted and socket heads. Head style affects torque delivery and access clearance, especially in accessory interface systems like M-LOK.
Key Firearm Fasteners Overview
| Fastener Type | Performance Requirement | Typical Material / Feature |
|---|---|---|
| Action & Frame Screws | Secure frame-to-barrel integrity under recoil | Alloy steel or stainless; torque-loc threadlocker |
| Optics & Accessory Screws | Precise alignment; repeatability | #8-32 or 10-24 UNC/UNF; self-locking finishes |
| Barrel Retention Bolts | Maintain preload; resist thermal expansion | Heat-treated alloy steel; rolled threads |
| M-LOK & Rail Mount Screws | Secure accessories; resist torque and vibration | M4/M5 or #8-32; zinc-nickel or black oxide finish |
| Trigger & Internal Pins | Precision tolerances; vibration resistance | Stainless or alloy steel; fine-tolerance machining |
Why Quality Fasteners Matter in Firearms
- Reliability: Low-grade bolts can loosen or fail—causing misfires or unsafe operating conditions.
- Accuracy: Proper preload and precision ensure consistent shot placement and sight alignment.
- Longevity: Corrosion-resistant fasteners preserve firearm life in harsh environments.
Metric Bolt: Your Expert Supplier for Firearm Fasteners
Metric Bolt delivers high-quality fasteners designed for firearms applications, including action screws, accessory hardware, barrel bolts, and rail mounts. We offer precision-manufactured stainless and alloy steel fasteners with protective coatings, torque-validation guidance, and traceable certification for mission-critical performance.
Need firearms-grade fasteners engineered for reliability and accuracy?
Contact Metric Bolt for expert sourcing, calibrated torque support, or certified part procurement.
