Chicago Pneumatic Extended Shaft Straight Die Grinder | CP3550-120ES | 12000 RPM | 1/4" (6 mm) Collet

Built for extended-reach deburring, chamfering, and finishing, the Chicago Pneumatic CP3550-120ES Straight Die Grinder delivers 12,000 RPM free speed for controlled material removal with mounted wheels, carbide burrs, and compatible abrasive accessories. The extended shaft helps reach into castings, welded assemblies, deep pockets, and recessed edges where a standard-length grinder may not provide enough access. Powered by a 1.5 HP / 1100 W governed motor, this model gives fabrication, foundry, and maintenance teams the power needed for intensive grinding work while running slower than the 18,000 RPM CP3550-180ES for better control on harder contact points.

The CP3550-120ES uses a 15/64" / 6.0 mm collet for holding compatible shank-mounted abrasives and carbide burrs. A governed motor helps maintain abrasive speed under load, which matters when the tool is pushed into a burr edge, casting seam, weld bead, or chamfering cut. The rear exhaust directs air away from the work surface, while the streamlined safety lever, spindle lock button, rotative inlet, aluminum body, and composite over-sleeve help make daily industrial grinding work easier to control.

Type: Extended Shaft Straight Die Grinder | Model: CP3550-120ES | SKU: 6151602350 | Free Speed: 12,000 RPM | Power: 1.5 HP / 1100 W | Collet Capacity: 15/64" / 6.0 mm | Air Consumption at Load: 55 CFM / 26 l/s | Air Inlet: 3/8" NPT | Working Pressure: 90 PSI / 6.3 bar | Hose I.D.: 3/8" / 10 mm | Length: 14.37" / 365 mm | Weight: 3.09 lb / 1.4 kg | Sound Pressure: 77 dB(A) | Sound Power: 88 dB(A) | Vibration Level: <2.5 m/s² | Exhaust: Rear | Governor Type: Ball | Main Material: Aluminum with Composite Over-Sleeve | Rotative Inlet: Yes | Spindle Lock: Yes | Starting System: Safety Lever

Features:

• Extended shaft configuration improves access into recessed surfaces, internal edges, castings, and hard-to-reach grinding points.
• 12,000 RPM free speed provides controlled material removal for mounted wheels, carbide burrs, chamfering, and finishing work.
• 1.5 HP / 1100 W governed motor helps maintain abrasive speed during intensive grinding, deburring, and fettling operations.
• Industrial Erickson collet supports 1/4" and 6 mm shank-mounted abrasives and carbide burrs.
• Streamlined safety lever supports controlled tool operation and helps reduce accidental start risk.
• Spindle lock button allows faster mounted point and carbide burr changes to reduce downtime between operations.
• Rotative inlet swivel helps prevent air hose knots and improves tool movement around fixtures and workpieces.
• Composite over-sleeve provides a lower-diameter grip surface with thermal insulation during extended use.

Applications:

• Metal fabrication: deburring holes, cleaning edges, chamfering parts, and blending small weld areas where extra reach is useful.
• Foundry and casting cleanup: removing flash, fettling casting seams, and reaching into recessed pockets or internal contours.
• Industrial maintenance and MRO: grinding repair parts, smoothing brackets, cleaning machine components, and preparing worn surfaces.
• Shipyard and structural repair: working around welded assemblies, stiffeners, frames, and fabricated components with a long-reach straight grinder.
• Toolroom and fixture work: controlled burr work on jigs, dies, molds, and machined parts where a slower 12,000 RPM grinder is preferred over higher-speed models.

FAQs:

• Q: What is the CP3550-120ES best used for?
  A: The CP3550-120ES is best used for extended-reach deburring, chamfering, fettling, and finishing with compatible mounted wheels and carbide burrs. The extended shaft helps when the work area is too deep or recessed for a standard straight die grinder.
• Q: How is the CP3550-120ES different from the CP3550-180ES?
  A: The CP3550-120ES runs at 12,000 RPM, while the CP3550-180ES runs at 18,000 RPM. Choose the 12,000 RPM version when you want more control with mounted abrasives or when the accessory and material call for a lower operating speed.
• Q: What collet size does this grinder use?
  A: The catalog lists a 15/64" / 6.0 mm collet capacity for this SKU. CP also references Erickson collet compatibility for 1/4" and 6 mm shanks in the CP3550 die grinder range, so confirm the exact collet setup required for your accessories before ordering replacement collets.
• Q: What air supply does the CP3550-120ES require?
  A: Chicago Pneumatic lists 55 CFM / 26 l/s air consumption at load and 90 PSI / 6.3 bar working pressure. Use a properly sized compressed-air system with clean, regulated, lubricated air to maintain tool speed under load.
• Q: Can this die grinder use any mounted point or carbide burr?
  A: No. The accessory must match the tool's collet size and must be rated for at least the grinder's 12,000 RPM free speed. Always verify shank size, maximum operating speed, and material suitability before mounting an abrasive accessory.

Looking for more information about Chicago Pneumatic Straight Die Grinder? Click here to view the Catalog.

For help selecting the correct Chicago Pneumatic Straight Die Grinders for your assembly application, call (800) 608-5210 or email info@intlairtool.com