Die grinders are a necessity for any shop. From deburring applications to heavy stock removal, grinders perform a wide range of finishing and grinding applications. With both electric die grinders and air die grinders (pneumatic grinders) available, we often get asked which type of die grinder is best, and which die grinder to use for your next application.
electric die grinders vs. air die grinders comparison
| ELECTRIC DIE GRINDERS | AIR DIE GRINDERS |
| Heavier than air tools | Lighter than electric tools |
| Power to motor does not equal the power to the spindle of the tool - typically less than 65% of the power (or rated wattage) arrives to the accessory or abrasive. Less overall power to the tool can equate to less productivity. | Power 'in' is equal to the power that reaches 'out' to the accessory or abrasive on the tool. More overall power to the tool can equate to more productivity. |
| Electric motors generate heat and require rest time to avoid overheating during extended continual use. | Air tools do not require a rest time and can run for hours at a time without risk of overheating. |
| Electric die grinders give off heat and can increase operator comfort in the winter. | Air die grinders can have moisture become trapped in the line and freeze in the winter. |
| Mobility of an electric grinder is impacted by the length of the power cord. Cordless grinders increase mobility significantly. | Mobility of an air grinder is impacted by need to have it attached to a compressor and hose. |
| Electric die grinders will typically require more frequent maintenance cycles (brush replacement is often required - using a grinder with a brushless motor is recommended.) | Air die grinders will typically require less frequent maintenance cycles (other than 2 bearings and a few nylon vanes, there are no wear parts, however, air lines will require maintenance). |
| Use of electric die grinders can be dangerous in explosive environments (risk of sparking) and extended use can cause the motor to burn. | Use of air die grinders is generally safer as no electricity is required, they run cool, plus they have a stalling mechanism that prevents tool burnout. |
CONCLUSION:
Electric grinders are ideal for home shops or where they will be used intermittently. Cordless electric grinders provide more mobility than their corded counterparts, and are increasingly available with more power, allowing better performance and longer run time. Brushless electric grinders require less maintenance, as they eliminate the need for brush replacement. While both types of grinders are highly versatile, only air grinders (pneumatic grinders) can withstand periods of extended use without rest, and this paired with an air grinder's significantly greater power make an air grinder (pneumatic grinder) better suited for heavy-duty, industrial applications. An air grinder's power, durability, and reliability make it our recommendation for professionals and fab shops, while an electric grinder's power and price point make it our recommendation for home shop machinists and DIYers.
