Section · Power tools

Power tools

Power tools are sold on peak numbers — RPM, in-lb, volts — that often measure the wrong thing. The number that keeps a grinding wheel together is rim speed; the number that decides your next decade of tool purchases is printed on the battery, not the tool; and the word "brushless" on the box means one specific mechanical change, not magic. The guides in this section trace each number to its spec sheet or standard.

Guides in this section

• Angle Grinders: The Numbers That Keep the Wheel Together
  Why rim speed, not RPM, is the number that keeps the wheel in one piece; the 4-1/2 in. / 11,000 RPM class read off the catalog plate; and what OSHA and ANSI B7.1 actually require.
• Picking a Cordless Battery Platform: The Lock-In Audit
  The four big 18V-class systems read from their own catalog counts and warranty documents, amp-hours turned into dollars per watt-hour, and a switching-cost worksheet.
• Brushless vs Brushed: What the Premium Actually Buys
  One rubbing contact removed, one controller added; the efficiency and service-life figures graded for what they are; and a use-frequency × failure-cost rule instead of a verdict.
• Drill, Impact Driver, or Impact Wrench: Which Job Is in Front of You?
  Three mechanisms, not three sizes: the fastener map by interface, and why torque figures across the three are not comparable.

Not yet rebuilt

The older site at this domain carried pages on wet/dry vacuums and jobsite radios. Those addresses point here until a guide worth reading exists for each. A shop-vacuum and dust-extraction guide is in preparation. Until a guide ships, its address stays dark.

Everything published in every section is on the guides index.