CDI 4004MFRMH – 3/4" Drive Micrometer Torque Wrench

The CDI 4004MFRMH is the entry point into CDI's 3/4-inch drive foot-pound family — a dual-scale micrometer click-type torque wrench covering 80–400 ft-lb (108.5–542.4 Nm) at 34.25 inches long and 10.30 lb. When a shop steps up to 3/4-inch drive, the work is categorically different from what 1/2-inch drive covers: turboprop engine mount hardware, propeller flange retention on PT6A-powered aircraft, main landing gear structural attach on heavier twins, and wheel and brake assembly work on business aircraft. The 4004MFRMH is built for that tier of maintenance with the drive size, handle length, and NIST-traceable documentation it demands.

When to step up from 1/2-inch to 3/4-inch drive

The 2503MFRMH tops out at 250 ft-lb. Propeller flange retention bolts on many turboprops spec at 200–300 ft-lb. Main landing gear strut attach hardware on heavier twins and entry business jets runs 250–400 ft-lb. Wheel and brake assembly hardware on turboprop singles and light business jets, heavy structural wing and fuselage fasteners, and high-torque GSE chassis hardware all exceed what a 1/2-inch drive wrench handles with confidence. The 4004MFRMH picks up where the 2503MFRMH leaves off, with a 3/4-inch drive and 34-inch handle that gives the operator the mechanical advantage to apply 300–400 ft-lb accurately and without strain.

Documentation-ready for certificated maintenance

Every 4004MFRMH 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 heaviest hand-wrench work in aviation and GSE

• 3/4" drive — the standard for high-torque aviation and GSE fastener work above 250 ft-lb
• 34.25" overall length provides the mechanical advantage needed for accurate torque at 300–400 ft-lb
• 5 ft-lb graduation — appropriate for AMM specifications stated in 5–25 ft-lb increments at this range
• 10.30 lb knurled metal handle built for sustained use on high-consequence structural 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 3/4" drive head with quick-release button for fast socket changes
• Audible click plus tactile impulse confirms torque in noisy hangar and shop 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 MRO shops and line technicians reach for the 4004MFRMH

• Propeller flange retention bolts on PT6A-powered turboprops and similar turbine aircraft (200–300 ft-lb)
• Main landing gear strut attach and drag brace hardware on piston twins and entry business jets (250–400 ft-lb)
• Engine mount attach bolts on turboprop singles and piston twins in the 200–350 ft-lb band
• Wheel and brake assembly hardware on turboprop singles and light business jets
• Heavy structural wing, spar, and fuselage attach hardware in MRO overhaul work
• GSE tow vehicle and ground power unit chassis structural fasteners above 250 ft-lb
• Aircraft tug wheel hub and drivetrain hardware requiring 3/4" drive torque documentation

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. The work the 4004MFRMH is used for — prop flange retention, landing gear attach, engine mounts — is among the most scrutinized in a Part 145 QCM. Our on-site ISO 17025-accredited calibration laboratory recertifies the 4004MFRMH and returns it with documentation that holds up under the closest audit.