Chicago Pneumatic CP 4608 Rivet Busters (The "Hell Dog")

Chicago Pneumatic CP 4608 Rivet Busters (CPS) — “Hell Dog” / “Boyer Buster”

If you need a pneumatic rivet buster that hits like a much larger paving breaker but still stays controllable in real-world demolition, the Chicago Pneumatic CP 4608 is the proven workhorse contractors keep coming back to. Known on jobsites as the Hell Dog (or Boyer Buster), the CP 4608 is widely used for concrete demolition and has become one of the stars of the CP range thanks to its low-frequency blow and serious hitting power.

Originally designed for cutting and forming metal rivets, the CP 4608 platform has evolved into a go-to solution for bridge deck work, rivet removal, bolt cutting, and general concrete breaking—the kind of tool you pull out when you want fast progress without stepping up to a much heavier breaker.

Why the CP 4608 Hits So Hard (Without Feeling Unmanageable)

The CP 4608 delivers a low blow frequency with impact energy that’s often compared to a breaker twice its weight, which is exactly why it’s so effective on thick concrete and stubborn rivets.

Key design elements that drive performance include:

• Special Boyer valve that makes the cylinder stroke effectively longer for more hitting power
• More consistent blow delivery thanks to the Boyer valve’s high-quality design
• Teasing throttle for progressive hitting frequency, giving you better control over a very powerful machine

CPS Safety + Uptime: Built to Prevent Damage (and Keep You Working)

The “new CPS” configuration adds critical safety and wear-management improvements:

• Stepped piston and stepped cylinder design to help prevent accidental piston ejection
• Stepped piston (hardened steel) for rugged durability in harsh conditions
• Buffer ring upgraded to 90 durometer rubber for longer service life

CPS also adds a smart wear-protection behavior: a wear-indicating groove alerts you when the bumper is worn, and if wear reaches a critical point, the tool is designed to bleed air and force the piston to stop—helping avoid expensive internal damage if the buster is pushed too far.

Configurations: Pick Your Handle (Same CP 4608 Power)

The CP 4608 is offered in two primary handle styles—both are the 8-inch stroke / 1,080 bpm setup:

• CP 4608 P (Open Grip / Outside Trigger)
• CP 4608 D (D-Handle / Inside Trigger)

The platform is also commonly referenced with cylinder choices:

• 11" cylinder (720 bpm)
• 8" cylinder (1,080 bpm)

The CP 4608 is the fast-hitting 8" / 1,080 bpm configuration, ideal when you want high production without jumping to a much heavier breaker class.

CP 4608 D Specs Snapshot (8" Stroke Rivet Buster)

Type: Rivet Buster

• Length: 23 in
• Air Consumption: 45 cfm
• Blows Per Minute: 1,080 bpm
• Air Inlet: 1/2 in
• Handle Type: D-handle, inside trigger
• Cylinder: Short cylinder (8-inch stroke)
• Chuck Size: 0.890 in x 1.125 in taper
• Chuck Type: Jumbo shank

Features (Straight to the Point)

• Among the best power-to-weight ratios available
• Teasing throttle for precise control
• Rugged design and components for reliable operation under tough conditions
• Stepped cylinder design for added safety
• Forged steel handle for long life in rugged environments
• Special Boyer valve for effectively longer stroke and more impact
• Stepped piston of hardened steel
• Multi-area exhaust routing designed to keep exhaust from interfering with your workspace
• Grooved barrel with lock spring retainer for easier steel changes
• Open swan neck handle option for better performance in tight spaces

Applications

Used for removing rivets in metal and concrete applications, including demolition and bridge work. Also ideal for general concrete demolition, bridge deck work, bolt cutting, and other tough removal tasks where controlled, heavy hitting power matters.

Recommended Setup (To Get Full Power and Longer Tool Life)

To keep the CP 4608 running hard and lasting longer, set it up correctly:

1. Use clean, dry air supply and run a water separator to keep moisture out of the tool.
2. Run an inline lubricator and use proper air tool oil.
3. Keep common wear parts on hand (buffer/bumper and sleeve-related wear items) to reduce downtime.

Steel Compatibility (Jumbo Shank Options)

Because the CP 4608 uses a Jumbo shank chuck, you can run a wide range of working steel depending on the job:

• Moil points (general breaking)
• Narrow chisels (edge work / controlled chipping)
• Rivet buster steels (rivet removal)
• Drift pin drivers (alignment work)
• Rippers (aggressive removal)
• Backout punches (stuck hardware situations)

The Bottom Line

The Chicago Pneumatic CP 4608 Rivet Buster is the culmination of decades of refinement: a tough, reliable pneumatic buster that delivers low-frequency, high-impact power with a control-focused teasing throttle and the safety-minded CPS stepped piston/cylinder design. If you want a demolition-capable “Hell Dog” that can take on bridge work, rivet removal, and serious concrete breaking without moving up to a much heavier breaker, the CP 4608 is the one.