The Borka Tools 18 Inch-Lbs Precision Torque Limiter (PTL-18) is a dedicated mechanical hand tool engineered to prevent fastener over-tightening during optics mounting and rifle maintenance. Preset at the factory to deliver 18 in-lbs (~2.03 Nm), it utilizes a mechanical slip mechanism to protect scope tubes from crushing and prevent stripped threads on delicate ring caps and base mounts. It operates entirely without batteries or electrical power, interfacing directly with standard 3/8" square drive handles on the input end and 1/4" hex shank screwdriver bits on the output.

Key Features

• Factory Preset Torque: Delivers a non-adjustable 18 in-lbs (~2.03 Nm) limit, calibrated according to the ISO-6789 procedure with typical accuracy of ±2% or better.
• Bi-Directional Internal Protection: Specifically calibrated for clockwise tightening while limiting torque in both clockwise and counter-clockwise directions to prevent internal mechanism damage during fastener removal.
• Standard Drive Compatibility: Designed with a female 3/8" square drive input to accept standard hand ratchets and a female 1/4" hex drive output socket for standard tool bits.
• Compact Mechanical Construction: Fully manual design requiring no external power or charging, measuring 3.0 inches in length and weighing 3.5 oz for easy inclusion in field kits.
• Traceable Identification: Features batch-specific laser-etched ID markings or a calibration label traceable to factory calibration standards.

Specifications

• Torque Setting: 18 in-lbs (~2.03 Nm), fixed/preset
• Calibration Accuracy: ±2% (ISO-6789 calibrated)
• Input Drive: 3/8" square drive (Female)
• Output Drive: 1/4" hex drive socket (Female)
• Outer Diameter (O.D.): 0.87 inches (22 mm)
• Length: 3.0 inches (76.2 mm)
• Weight: 3.5 oz (approx. 99 g)
• Operation Mode: Manual hand-tool use only

Who is the Borka Tools 18 Inch-Lbs Precision Torque Limiter for?

• Precision rifle competitors mounting imperial optics — relies on a factory-calibrated ±2% accuracy at a fixed 18 in-lbs to secure imperial-spec optic mounts, scope ring caps, and base screws to exact tension without crushing scope tubes.
• Hunters maintaining optic rings and mounts in the field — utilizes a compact 3.0 inches length, 0.87 inches outer diameter, and 3.5 oz total weight for a mechanical precision torque limiting driver that fits easily into mobile toolkit pouches without requiring batteries.

Less suitable for: High-speed motorized drivers or electric power tools (hand-tool use only), fasteners requiring higher torque limits such as action screws at 45–65 in-lbs (which require an adjustable multi-torque driver or higher-rated dedicated limiter), miniature fasteners below 5/64" hex bit size where bits cannot tolerate 18 in-lbs of force, or low-torque turret adjustments requiring 4–8 in-lbs (which require a lower-range precision torque driver).