Ingersoll Rand 307B 1/4 Air Die Grinder - Compact 28,000 RPM

Our review of the Ingersoll Rand 307B 1/4 air die grinder finds it to be a compact, professional-grade tool best suited for metalworkers, fabricators, and serious DIYers who need consistent speed in tight spaces. The single biggest reason to buy is its combination of a high-revving vane motor and lightweight aluminum housing, which delivers 28,000 rpm and enough power for grinding, deburring and polishing while remaining easy to control. In real shop use the 307B feels balanced, durable, and engineered to last under repeated use.

Key Features

• Powerful vane motor: Delivers 0.25 hp at 28,000 rpm for fast material removal on steel and other metals.
• Lightweight compact design: The slim, straight body fits into tight spots and reduces operator fatigue during prolonged use.
• Ball-bearing construction: Provides improved balance and reduced vibration for smoother handling and longer tool life.
• Safety-lock throttle lever: Integral safety lock helps prevent accidental start-up for safer shop operation.
• Front exhaust and lubricating wick: Front exhaust keeps the work area cleaner while the built-in wick helps extend internal component life.
• Included accessories: Comes with two wrenches plus 1/4 in and 6 mm collets for compatibility with common accessories.

Who It's For

The 307B is aimed at mechanics, metal fabricators, and hobbyists who need a reliable, high-speed straight die grinder for tasks such as porting, grind finishing, deburring, and light cutting. Its compact size and balance make it especially useful where reach and access are limited.

Those who should look elsewhere include users who need extremely high torque for heavy material removal or those requiring cordless convenience; this is a pneumatic tool and depends on an air supply. Also, buyers seeking an all-in-one kit with a wide range of accessories might prefer a different package.

Pros & Cons

Pros

• High 28,000 rpm speed that handles detailed grinding and polishing efficiently.
• Durable aluminum housing and ball-bearing construction that lower vibration and increase longevity.
• Lightweight, straight profile that improves reach and comfort in tight areas.
• Includes essential collets and wrenches so it is ready for common attachments out of the box.

Cons

• As an air tool it requires a compatible compressor and hoses, which adds to total system cost.

Specifications

Model	307B
Type	Straight air die grinder
Power	0.25 hp (0.19 kW)
Speed	28,000 rpm
Construction	Ball-bearing with aluminum housing
Collets included	1/4 in and 6 mm
Safety	Integral safety-lock throttle lever

Our Verdict

The Ingersoll Rand 307B is a well-built, compact pneumatic die grinder that offers high rpm and good balance for detail work, making it excellent value for professionals and dedicated hobbyists. Buy it if you already use air tools and need a durable, lightweight grinder that reaches tight spaces and holds up under regular shop use.

Frequently Asked Questions

Does the 307B come with collets?
Yes. The tool includes 1/4 in and 6 mm collets plus two wrenches for accessory changes.

Is the exhaust front or rear?
The grinder features a front exhaust to help keep the work surface clearer of expelled air.

What kind of maintenance does it need?
Regular lubrication via the built-in wick and routine inspection of ball bearings and collets will keep the unit performing well.