CDI 1502MRMH – 3/8" Drive Micrometer Torque Wrench
The CDI 1502MRMH occupies a specific and deliberate niche in the CDI inch-pound lineup: a 3/8-inch drive wrench covering the same 20–150 in-lb (2.3–16.9 Nm) range as the 1/4-inch drive 1501MRMH, but built around the larger drive that most A&P mechanics already have sockets for. When the fastener calls for a 3/8-inch drive socket — a deep well, a thin-wall, or a specialty socket that doesn't exist in 1/4-inch — the 1502MRMH is the right tool without sacrificing the precision documentation aviation maintenance demands.
The documentation behind it satisfies certificated maintenance requirements
Every 1502MRMH ships with its own serial number and a matching certificate of calibration traceable to the National Institute of Standards and Technology (NIST), satisfying tool control requirements in FAA-accepted maintenance programs, Part 145 repair station Quality Control Manuals, and ISO 9001 quality management systems. Meets or exceeds ASME B107.14 and ISO 6789. Accuracy: ±4% CW, ±6% CCW of indicated value from 20–100% of full scale.
Why 3/8" drive matters in the 20–150 in-lb range
- Compatible with the full range of 3/8" drive sockets already in most aviation tool kits — deep wells, thin-walls, specialty sockets that don't exist in 1/4" drive
- Better socket retention and reduced flex near the top of the range (100–150 in-lb) compared to 1/4" drive
- Knurled metal handle withstands daily professional shop use — not the lightweight composite grip found on consumer alternatives
- Spring-loaded pull-down lock ring positively locks torque settings against drift mid-sequence
- Laser-marked dual scale reads in-lb and Nm simultaneously — no conversion chart needed
- Audible click plus tactile impulse confirms torque in noisy hangar 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 use the 1502MRMH
- Spark plug installation — 3/8" drive thin-wall spark plug sockets are the standard in most tool kits
- Oil drain plugs and oil filter adapter fittings on Continental and Lycoming engines
- Alternator, vacuum pump, and magneto mounting hardware
- Exhaust flange and heat muff fasteners on light aircraft engines
- General airframe hardware throughout the 20–150 in-lb band requiring a 3/8" drive socket
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. Unlike mega-retailers who stock this wrench alongside consumer hand tools, we understand exactly what it means to keep a torque wrench in a certificated tool crib. Our on-site ISO 17025-accredited calibration laboratory means that when the 1502MRMH comes due for recertification, you send it back to an aviation specialist — not a generic cal lab that's never seen a maintenance manual.
| General Information | |
|---|---|
| Part # | 1502MRMH |
| Manufacturer | CDI |
| Specifications | |
|---|---|
| Accuracy (CCW) | |
| Accuracy (CW) | |
| Calibration Certificate | Individually serialized, NIST-traceable |
| Country of Origin | USA |
| Cycle Rating | 5,000 cycles minimum |
| Drive Size | 3/8" |
| Graduation | 1 in-lb |
| Handle | Knurled metal, dual scale, laser marked |
| Head Type | Fixed ratcheting, quick-release button |
| Indicator | Audible click + tactile impulse |
| Lock Mechanism | Spring-loaded pull-down lock ring |
| Overall Length | 10.15 in |
| Standards | ASME B107.14, ISO 6789 |
| Torque Range | 20 |
| Warranty | 1-year manufacturer |
| Weight | 0.90 lb |
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AIRCRAFT COMPATIBILITY
This item is for use on all aircraft.
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QUESTIONS & ANSWERS
Yes. The 1502MRMH ships with an individually serialized, NIST-traceable certificate of calibration and meets ASME B107.14 and ISO 6789 — the documentation specifications typically required in Part 145 repair station Quality Control Manuals. Always verify against your facility's specific RSM requirements.
Both cover the same 20–150 in-lb (2.3–16.9 Nm) torque range with the same ±4% CW accuracy and NIST-traceable certification. The only difference is drive size — the 1501MRMH uses a 1/4-inch drive and the 1502MRMH uses a 3/8-inch drive. Choose the 1502MRMH when your application requires a 3/8-inch drive socket, such as a spark plug socket or deep-well that doesn't exist in 1/4-inch.
The 1502MRMH covers 20–150 in-lb (2.3–16.9 Nm) in 1 in-lb increments. Accuracy is ±4% clockwise and ±6% counter-clockwise of indicated value from 20% to 100% of full scale — consistent with tolerances cited in aircraft maintenance manuals for general structural fasteners.
Yes. Pilot John International operates an ISO 17025-accredited, NIST-traceable calibration laboratory. We can recalibrate the 1502MRMH and issue a new individually serialized certificate. Contact us directly for current pricing and turnaround time.
