The Borka Tools 25 Inch-Lbs Precision Torque Limiter (PTL-25) is a dedicated mechanical tool engineered to prevent over-tightening of firearm optics mounts, scope rings, base mounts, and rail accessories. Calibrated according to ISO-6789 procedures, it delivers a fixed tightening torque limit of 25 in-lbs (~2.82 N·m) with a factory calibration tolerance typically within ±2% (often within ±1%). Operating entirely manually without batteries or electrical power, the compact unit measures 0.87 inches in outer diameter by 3.0 inches in length and weighs 3.5 ounces, making it highly portable for range bags and armorer workbenches.

Key Features

• Factory Preset Torque: Non-adjustable 25 in-lbs torque limit calibrated strictly for precise clockwise (CW) fastener tightening.
• Internal Calibration Mechanism: Incorporates an internal factory adjustment screw system designed for high repeatability beyond standard generic limiters.
• Dual Rotation Protection: Features internal protection that limits torque in both clockwise and counter-clockwise directions to safeguard the internal mechanism from damage during fastener removal.
• Standard Drive Interfaces: Configured with a 3/8" square female input drive for hand ratchets and a 1/4" hex female socket output drive for standard screwdriver bits.
• Traceable Identification: Marked with a laser-etched ID mark and supplied with a certificate of calibration or an on-body calibration label.

Specifications

• Torque Setting: 25 in-lbs (~2.82 N·m)
• Calibration Tolerance: Typically within ±2% (ISO-6789 procedures)
• Input Drive: 3/8" square female (F)
• Output Drive: 1/4" hex female (F) socket
• Length: 3.0 inches (approx. 76.2 mm)
• Outer Diameter: 0.87 inches (approx. 22.1 mm)
• Weight: 3.5 ounces (approx. 99.2 g)
• Operation: Manual hand use only

Who is the Borka Tools 25 Inch-Lbs Precision Torque Limiter for?

• Precision rifle shooters mounting scopes — requires a fixed 25 in-lbs limit through a standard 1/4" hex female socket drive to secure heavier optic rings and base mounts precisely without crushing scope tubes.
• Armourers and firearm enthusiasts — benefits from a compact 3.5 ounces fixed torque limiter tool with a 3/8" square female drive for routine field maintenance and assembly of rifle chassis and rail fasteners.

Less suitable for: Applications requiring torque settings other than 25 in-lbs (such as 15–18 in-lbs for light ring caps or 45–65 in-lbs for heavy action screws), which require an adjustable multi-torque driver or an alternate fixed torque limiter model; small hex bits under 5/64" (2mm) that fall below the 25 in-lbs working strength; or motorized power drivers and drills, which cause mechanical failure and require manual hand-operated ratchets instead.