JET 1/4in 1 HP Extended Die Grinder

Description

Short die grinders lack the reach needed to blend deep interior pipe welds. The JET 1/4in 1 HP Extended Die Grinder reaches five inches beyond standard grinders to smooth unreachable metal joints. Operating at 90 PSI with a full 1-horsepower motor, this tool spins at 18,000 free speed RPM. Heavy side load leverage against the long extension housing accelerates needle roller bearing wear.

An oversized ductile iron motor cylinder houses four phenolic composite rotor vanes designed for high thermal stability under load. The case-hardened steel drive shaft runs on heavy-duty double ball bearings supported by an extended steel housing neck. The precision 1/4-inch steel collet assembly maintains true concentricity to prevent burr chatter under aggressive side pressure. Sintered bronze exhaust mufflers dissipate venting air pressure smoothly. Water condensation inside shop lines pits the internal rotor shaft and bearing races, triggering high-frequency tool vibration and bearing seizure.

Extended Shaft Rotary Hardware Specifications

Deep-cavity metal finishing requires sustained rotational torque without motor bogging under aggressive burr contact. The extended drive architecture combines high horsepower with a rigid multi-bearing steel spindle housing.

• 1/4-inch NPT air inlet draws high air volume to sustain full one-horsepower motor torque output
• Extended five-inch steel neck housing reaches deeply into fabricated tubes and recessed casting ports
• Precision 1/4-inch heat-treated collet secures heavy carbide burr shanks to prevent high-speed slip
• Phenolic composite rotor vanes resist moisture wash-out and thermal expansion during heavy grinding runs
• Self-locking safety throttle lever prevents accidental motor engagement when setting the tool on benches
• Ergonomic composite sleeve insulates the operator forward hand from cold steel neck temperatures
• Rear exhaust deflector vents cold pneumatic exhaust discharge and lubricant mist away from work surfaces

Motor Dyno Telemetry Load Analysis

Dynamic air consumption demands 24 CFM at 90 PSI dynamic under full carbide burr stall conditions. Free speed spins up to 18,000 RPM, slowing down to 13,500 RPM under aggressive operator surface pressure. Pressure drop through a 50-foot 3/8-inch hose measures 15 PSI without high-flow V-style couplers. Adiabatic expansion drops internal exhaust temperatures to 20°F, creating muffler frost in humid plant environments. Rotational torque output measures 5.8 ft-lbs at peak load. Operator sound levels reach 86 dBA.

Fabrication Shop Directives Application Limits

Extended die grinders generate extreme torsional leverage against internal drive bearings. Light utility shops with small 1/4-inch air supply lines should not purchase this heavy tool because low airflow drops horsepower output by half. Forcing oversized cut-off wheels onto this 1/4-inch collet will bend the extended spindle shaft immediately.

• Feed six drops of pneumatic tool oil directly into the air inlet port before each fabrication shift
• Check the runout of the extended spindle shaft using a dial indicator to prevent bearing destruction
• Blow abrasive metal grinding dust away from the rear exhaust ports before storing the tool

Commercial Warranty Terms Box Contents

JET backs this industrial pneumatic grinder with a comprehensive 2-Year limited warranty against mechanical failures and manufacturing defects. The factory unboxing package contains the 1 HP extended die grinder, two collet service wrenches, a 1/4-inch industrial air fitting, and the operating instruction manual.