Luth AR Trigger Group 3 Piece Fits AR 15 Includes Trigger Hammer and Disconnector Manganese Phosphate Finish Black LRPK THD LUTHLRPK THD UPC 859819007614
Product Description
The Luth-AR® AR-15 3-Piece Trigger Group (SKU: LRPK-THD / UPC: 859819007614) delivers authentic, USGI Mil-Spec fire control geometry for custom lower receiver builds, duty rifle overhauls, and armorer spare parts staging. Purpose-built for builders who already possess custom spring kits or upgraded anti-walk pins, this 3-piece steel sub-assembly includes the bare Mil-Spec AR-15 Trigger, Hammer, and Disconnector without redundant hardware.
Unlike budget aftermarket fire control components that rely on brittle Metal Injection Molding (MIM), Luth-AR manufactures the LRPK-THD assembly using investment-cast and precision-machined ordnance steel heat-treated to strict military print specifications. Each component is finished in a dense, non-reflective black Manganese Phosphate (Parkerized) coating whose micro-crystalline surface structure traps CLP and high-pressure sear grease, mitigating galling, corrosion, and premature sear engagement wear over thousands of cycles.
Machined to accept standard 0.154-inch small-pin hammer and trigger pins, this 3-piece fire control group pairs seamlessly with both standard Mil-Spec spring weights and reduced-power aftermarket performance springs (such as JP Enterprises 3.5 lb or 4.5 lb spring sets). Whether restoring a worn service carbine back to crisp factory reset tolerances or assembling a bespoke lower receiver from the ground up, Luth-AR provides American-made mechanical reliability.
*Armorer Bench Notes & Real-World Staging Guidance:*
Fitment Matrix: Fits all Mil-Spec AR-15, M4, M16, and DPMS Gen 1 .308 lower receivers utilizing standard 0.154" fire control pins. CRITICAL ARMORER NOTE: This SKU includes the 3 steel components ONLY (Trigger, Hammer, Disconnector). It does NOT include the trigger spring, hammer spring, disconnector spring, or 0.154" trigger/hammer pins. NOT compatible with older Colt large-pin (0.170") lower receivers.
- Ensure the host firearm is completely clear, magazine removed, and chamber visually and physically verified empty before separating the upper and lower receivers.
- Stage your separately sourced disconnector spring (installing the wider flared coil base downward into the rear trigger slot) and position the Luth-AR disconnector onto the trigger channel.
- Apply a light film of synthetic firearm grease to the primary trigger sear nose, disconnector hook, and hammer notch, then insert the trigger assembly into the lower receiver fire control pocket and secure with a 0.154" trigger pin.
- Orient your hammer spring legs rearward (resting atop the trigger pin grooves to capture the pin detents), align the Luth-AR hammer bore with the receiver, and drive the 0.154" hammer pin flush until the internal J-spring locks into the center pin annular groove.
- Perform a complete 3-stage dry-fire function check (safe blockage, primary sear break, held-trigger disconnector catch, and audible tactile reset) prior to live-fire staging.
Key Features
- Zero-MIM Ordnance Steel Construction: Investment-cast and precision-machined to USGI Mil-Spec blueprints and Rockwell hardness tolerances for lifetime structural integrity.
- Manganese Phosphate Surface Treatment: MIL-STD-171 Parkerized finish absorbs lubricants directly into the steel surface to prevent corrosion and smooth out sear engagement.
- Builder-Optimized 3-Piece Configuration: Includes the bare AR Trigger, AR Hammer, and AR Disconnector—ideal for pairing with custom reduced-power springs and anti-rotation pin kits.
- Standard 0.154" Pin Architecture: Precision-reamed bores ensure drop-in fitment across all standard Mil-Spec AR-15 and M4 lower receivers.
- 100% American Manufactured: Proudly engineered and machined in the USA by Luth-AR to uncompromising armorer quality control standards.
Product Specifications
- Brand: Luth-AR®
- Model/Series: AR-15 3-Piece Trigger Group
- MPN / SKU: LRPK-THD / LRPKTHD
- Distributor SKU: LUTHLRPK-THD
- UPC: 859819007614
- Platform Compatibility: AR-15 / M4 / M16 (0.154" Mil-Spec Pin Receivers)
- Material: Heat-Treated Ordnance Alloy Steel (Zero MIM)
- Finish / Color: Manganese Phosphate (Black)
- Included Components: AR Trigger, AR Hammer, AR Disconnector (Springs & Pins Not Included)
- Country of Origin: USA
