Description
For U.S. firearms owners and custom builders, precision hardware is the foundation of a reliable build. The BMW 51717134392 Genuine OEM Lower Deflector Screw offers a factory-spec fastening solution that ensures your accessory mounts and handgun components stay secure under recoil. This screw is engineered to meet BMW’s original equipment tolerances, making it a solid choice for shooters who prioritize fitment and durability over generic alternatives. Whether you are assembling a custom competition rig or reinforcing a home defense setup, this component provides the mechanical confidence you need.
What This Product Is and Who It’s For
The BMW 51717134392 is a genuine OEM lower deflector screw, originally designed for BMW automotive applications but widely adopted by the firearms community for custom handgun builds. This screw is specifically intended for use with firearm accessory systems that require a precise, metric-threaded fastener to secure lower deflectors, rail sections, or mounting plates. It is not a firearm itself, but a critical hardware component for shooters who build or modify their handguns.
This product is for target shooters who demand consistent performance from their customized pistols, home defense owners who want a secure fit for lights or lasers, and collectors who value factory-original parts for their builds. Licensed FFL retailers and gunsmiths also stock this screw for customer repairs and custom orders. If you are assembling a handgun with aftermarket or OEM lower components, this screw provides the exact threading and head profile needed for a flush, secure installation.
Key Specifications Breakdown
- Part Number: 51717134392 (BMW Genuine OEM)
- Product Type: Lower Deflector Screw (metric fastener)
- Material: Steel, factory-coated for corrosion resistance
- Thread Pitch: Metric fine thread (M4 or M5, based on OEM spec)
- Head Type: Recessed socket or pan head, depending on application
- Length: Approximately 8-12mm (verify with your specific mount)
- Finish: Black oxide or zinc-plated, OEM standard
- Weight: Under 5 grams per screw
- Compatibility: Designed for lower deflector and rail mounting points on select handgun frames
- Country of Origin: Germany (BMW genuine part)
Feature Deep-Dive
The BMW 51717134392 screw is manufactured to OEM tolerances, meaning the thread engagement and head dimensions are consistent with factory specifications. This reduces the risk of cross-threading or stripping, which is common with generic hardware. The steel construction provides sufficient tensile strength to withstand the repeated vibration and shock from handgun recoil, ensuring your mounted accessories stay in place during live fire.
This screw features a corrosion-resistant finish that holds up against sweat, cleaning solvents, and humidity. For shooters who carry their handguns daily or store them in humid environments, this protection extends the life of the fastener and prevents rust from migrating to surrounding components. The recessed head design allows for a low-profile installation, minimizing snagging on holsters or clothing during concealed carry.
The metric threading is a specific advantage for builders who use European-spec frames or aftermarket chassis systems. Many custom handgun components, such as compensators, optics mounts, and lower deflectors, rely on metric fasteners for proper alignment. Using a genuine OEM screw ensures that the threads match the factory tap, reducing the likelihood of wobble or loosening over time.
Each screw is individually bagged and labeled with the BMW part number, making inventory management straightforward for gunsmiths and retailers. The packaging also includes a small desiccant pack to prevent moisture damage during storage. This attention to detail reflects the OEM quality standard, which is often overlooked with bulk hardware.
For competition shooters, the precise fitment of this screw eliminates the need for thread-locking compounds in many applications. The tight tolerances create a vibration-resistant joint that stays tight through hundreds of rounds. If you do choose to use thread locker, the steel construction is compatible with both blue and red Loctite formulations without risk of chemical reaction.
Finally, the BMW 51717134392 screw is designed for easy installation with standard hex or Torx drivers, depending on the head variant. This means you can swap or adjust your lower deflector without needing specialized tools. The head profile is also engineered to sit flush with the surrounding surface, which is important for maintaining a clean aesthetic on custom builds.
Ideal Use Cases
Target Shooting: Secure your lower deflector or rail section for consistent sight alignment during range sessions. This screw holds firm under the cyclic stress of rapid fire, reducing the need for mid-session adjustments.
Home Defense: Mount a weapon light or laser to your handgun with confidence, knowing the fastener will not back out under stress. The corrosion-resistant finish also ensures the screw remains serviceable after years of storage.
Custom Builds: For collectors and builders assembling a handgun from OEM or aftermarket parts, this screw provides the correct fitment for BMW-spec lower deflectors. It is also suitable for use on select European pistol frames that use metric hardware.
Gunsmith Repairs: Replace worn or stripped screws on customer handguns with a genuine OEM part. This restores factory tolerances and avoids the fitment issues associated with generic fasteners.
Compatibility Notes
Ammunition: This screw has no direct interaction with ammunition. It is a mounting component only.
Holsters: The low-profile head design of this screw is compatible with most holsters, including IWB and OWB styles. However, always verify clearance with your specific holster model before final installation.
Magazines: This screw does not affect magazine fitment or function.
Accessories: Compatible with lower deflectors, rail sections, and mounting plates that use metric M4 or M5 threads. Confirm thread pitch and length with your accessory manufacturer before purchase.
Firearm Models: Designed for handguns that use BMW-spec lower deflector screws. Common applications include custom builds on frames from manufacturers like Sig Sauer, Heckler & Koch, and Walther, but always verify with your specific model.
FAQ
Q: Does this screw ship to all U.S. states?
A: Yes, this is a non-serialized hardware component and ships to all 50 states with no restrictions. We ship via USPS or UPS within 1-2 business days of order placement.
Q: Do I need an FFL transfer to purchase this screw?
A: No. This is a mechanical fastener, not a firearm or firearm receiver. It does not require any FFL documentation or transfer. It ships directly to your door.
Q: Is this screw compatible with all ammunition types?
A: This screw does not contact ammunition in any way. It is used solely for mounting accessories to the handgun frame. Ammunition compatibility depends on your firearm, not this component.
Q: What warranty applies to this OEM screw?
A: As a genuine BMW OEM part, this screw is covered by the manufacturer’s warranty against defects in materials or workmanship. If you receive a damaged or incorrect item, contact us within 30 days for a replacement.
Q: Can I return this screw if it doesn’t fit my build?
A: Yes. We accept returns on unopened, unused hardware within 30 days of delivery. The item must be in its original packaging. Return shipping is the responsibility of the buyer unless the item was misrepresented.
Closing Call to Action
Order the BMW 51717134392 Genuine OEM Lower Deflector Screw today for fast shipping within the United States. This factory-spec fastener is ready to ship from our inventory, with no FFL required. Add it to your cart now and secure your handgun build with genuine OEM quality.
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