AP Astro Pneumatic Tool Company 401K THOR 0.401" Long‑Barrel Air Hammer — 3-5/8" Stroke, Vibration‑Damping Internal Brake

The Astro Tools 401K THOR is a long-barrel, 0.401" shank air hammer built for maximum impact and controllable power in heavy automotive and industrial work.

Designed by AP Astro Pneumatic Tool Company, the 401K THOR combines a long stroke, ported valvebody, and a vibration‑damping internal brake so you get high-performance blows without excessive operator fatigue. It ships as a bare tool (bits sold separately) and accepts a 0.401" chisel shank, making it a go-to for stubborn rivets, seams, and demolition tasks where reliability and power matter.

How does the 401K THOR deliver more power than standard air hammers?

The 401K uses a long 3-5/8" piston stroke and a ported valvebody tuned to maximize per-stroke impact while keeping stroke speed efficient at 2,100 BPM. That combination boosts delivered energy so the hammer competes with premium truck-stock tools.

• 3-5/8" piston stroke for deeper impact.
• Ported valvebody engineered for stronger blows.
• 2,100 BPM stroke rate balances force with control.
• 0.401" chisel shank fits heavy-duty bits.

Can I control the power output for delicate versus heavy work?

Yes — the THOR includes a redesigned tilt-valve trigger that provides smooth, fingertip power adjustment. The trigger lets you dial back force for lighter tasks or open it up for full-throttle demolition without swapping tools.

• Tilt valve trigger for variable power modulation.
• Sensitive response enables fine control during finish work.
• Full power available instantly for stubborn fasteners.
• Rotatable forward grip aids positioning and leverage.

What features reduce vibration and operator fatigue during long jobs?

Inside the 401K THOR is an internal brake vibration-damping system that absorbs shock between blows, reducing hand and arm strain. Coupled with a rotatable forward grip and an ergonomic layout, the tool stays more comfortable through extended use.

• Internal brake system for lower vibration transfer.
• Rotatable forward grip improves comfort and control.
• Lightweight-for-power design at 5.31 lb net weight.
• Compact 10.25" length for tight spaces.

What air supply and accessories do I need to get the best performance?

Optimal operation is at 90 PSI using a 3/8" hose and Hi‑Flo fittings recommended to maintain airflow. The 401K has a 1/4" NPT inlet and comes with a quick‑change chuck; chisels and rivet bits must be purchased separately.

• Air inlet: 1/4" NPT; recommended 90 PSI operating pressure.
• Hose size: 3/8" to support consistent airflow.
• Hi‑Flo fittings suggested for maximum delivery.
• Includes quick-change chuck; bits sold separately.

Who is this for: The Astro Tools 401K THOR 0.401" Long Barrel Air Hammer is built for professional mechanics, body shop technicians, and industrial maintenance crews who need a high-impact, controllable air hammer for heavy-duty riveting, cutting, and demolition tasks. If you want a compact yet powerful hammer with vibration reduction and fingertip power control, the 401K is suited for demanding daily use where tool-truck level performance is required.