Mountain impact wrenches: A shooting match with two air guns

For this tool review, I chose a pair of pneumatic impact wrenches from Mountain Pneumatic Tools Co. Ltd., one with 3/8-inch drive and one with 1/2-inch drive (available exclusively from authorized Toolweb distributors). While the brand may not carry the fame of other well-known manufacturers, these two guns functioned well and survived my in-shop abuse with flying colors.

When the manufacturer described these guns as “ergonomic,” they weren’t kidding. The rubberized grips are very comfy, and the weight is well distributed for good balance. One of the niceties I noticed right off the bat was how the upper rubberized grip area extends for the top of the hand (web, knuckle and top of forefinger) and the thumb, offering a nice, cushy contact for a very pleasing grip. The surface of the rubber grip area provided a secure grip even with an oil-soaked hand.

The rotary directional/torque output control features a heavy-duty composite dial that’s easy to operate and features a good “feel” (with noticeable detents). The trigger is also shaped with the hard-working tech in mind, with a nice fat and radiused profile that doesn’t dig into your finger. Very comfy.

While I had the two sample wrenches in my shop, I couldn’t resist the urge to punish them, just for the sake of checking out their durability. Plastic composites have come a long way over the years. I dropped the wrenches onto my concrete floor repeatedly and I even threw them across the shop, allowing them to bash into and bounce off of the floor. They continued to operate perfectly and neither the composite bodies nor the aluminum noses broke. I also hammered the tools mercilessly while breaking old, rusty/crusty bolts from a few old engine cores. On one engine (an old junk Pontiac big block), I had a few particularly stubborn head bolts. The 1/2-inch drive unit hammered away until it snapped the 7/16-inch bolt (the gun got very hot due to the abuse, but kept working perfectly afterwards). During the prolonged hammering, the grip provided ample vibration insulation for my hand. I basically tried to break these guns, but to no avail. They kept functioning and maintained their torque.

Based on my own review of these two specific models, I’d definitely recommend the Mountain brand as one to consider when you’re in the market for additional impact wrenches.

SPECIFICATIONS

MTN7215

Drive: 3/8-inch square drive

Body material: Composite with aluminum nose

Bolt capacity: 1/2-inch

Max. torque forward: 245 ft.-lbs.

Max. torque reverse: 280 ft.-lbs.

Speed: 12,000 rpm

Weight: 2.65 lbs.

Mfg. suggested retail price $199.99

MTN7235

Drive: 1/2-inch square drive

Body material: Composite with aluminum nose

Bolt capacity: 3/4-inch

Max. torque forward: 780 ft.-lbs.

Max. torque reverse: 950 ft.-lbs.

Speed: 7,500 rpm

Weight: 4.5 lbs

Mfg. suggested retail price $208.99

Features of both models:

 • Through-handle exhaust

 • Lightweight ergonomic design

 • High power (three forward positions, one reverse)

 • Twin hammer / double-blow clutch

SOURCE

To learn more about the complete line of Mountain brand tools, see www.toolweb.com or check with your tool distributor.   ●