CDI 2503MFRMH – 1/2" Drive Micrometer Torque Wrench

The CDI 2503MFRMH is a 1/2-inch drive, dual-scale micrometer click-type torque wrench covering 30–250 ft-lb (40.7–338.9 Nm) — the highest-range 1/2-inch drive wrench in the CDI foot-pound metal handle family. At 24.40 inches it is four inches longer than the 1503MFRMH, providing the mechanical advantage needed to deliver accurate, repeatable torque at 200–250 ft-lb on a 1/2-inch drive. If the work regularly exceeds 150 ft-lb, this is the tool — and if it doesn't quite need 3/4-inch drive, this is the reason to stay in the 1/2-inch class.

The 1/2-inch drive wrench for heavy airframe and GSE work

Engine mount attach bolts on heavier singles and light twins, main landing gear structural attach hardware, wheel axle nuts on heavier GA aircraft, and fixed-pitch propeller retention hardware frequently spec at 150–200 ft-lb or beyond — territory the 1503MFRMH cannot reach. The 2503MFRMH covers it with a 1/2-inch drive and NIST-traceable documentation. For GSE maintenance, tug and tractor wheel hub hardware, ground power unit chassis fasteners, and tow bar lug hardware regularly call for 100–250 ft-lb, making the 2503MFRMH the practical choice over a heavier 3/4-inch drive tool for line and shop technicians who work in both environments.

Documentation-ready for certificated maintenance

Every 2503MFRMH ships individually serialized with a NIST-traceable certificate of calibration, satisfying traceability requirements in FAA-accepted maintenance programs, Part 145 repair station QCMs, and ISO 9001 quality systems. Meets or exceeds ASME B107.14 and ISO 6789. Accuracy: ±4% CW, ±6% CCW of indicated value from 20–100% of full scale.

Built for the upper half of the foot-pound range

• 24.40" overall length — four inches longer than the 1503MFRMH, providing mechanical advantage at 200–250 ft-lb
• 1/2" drive keeps the tool practical for line technicians working in both aviation and GSE environments
• 1 ft-lb graduation — consistent with maintenance manual specifications at this torque level
• Knurled metal handle at 3.15 lb withstands sustained use on heavy structural and drivetrain sequences
• Spring-loaded pull-down lock ring locks the setting through multi-fastener torque sequences
• Laser-marked dual scale reads ft-lb and Nm simultaneously — no conversion chart needed
• Fixed ratcheting 1/2" drive head with quick-release button for fast socket changes
• Audible click plus tactile impulse confirms torque in noisy hangar and ramp environments
• Rated to a minimum of 5,000 operating cycles
• Made in the USA by CDI Torque Products, a Snap-on Industrial Brands company

Where A&P mechanics and line technicians reach for the 2503MFRMH

• Engine mount attach bolts on heavier light singles and light twins (150–200 ft-lb)
• Main landing gear structural attach hardware and drag brace fasteners
• Wheel axle nuts on heavier GA aircraft and turboprop singles (150–250 ft-lb)
• Fixed-pitch propeller retention hardware on Continental and Lycoming powered aircraft
• GSE tug and tractor wheel hub hardware and drivetrain fasteners (100–250 ft-lb)
• Ground power unit chassis and mounting hardware on FBO and MRO fleets
• Aircraft tow bar pin, lug, and attachment hardware

Why source aviation tooling from Pilot John International

Pilot John International is an aviation-specialist distributor — not a general industrial catalog. We serve Part 145 repair stations, FBOs, MRO operations, and flight schools across the U.S. We understand that landing gear attach hardware, engine mount bolts, and prop retention fasteners are among the highest-consequence work an A&P does — and that the torque wrench used on them needs a current, defensible NIST-traceable certificate. Our on-site ISO 17025-accredited calibration laboratory recertifies the 2503MFRMH and returns it with documentation that holds up under audit.