Methodology

How we source every claim

We don't run a test lab, and we won't pretend to. Every number on this site traces to a manufacturer spec sheet, a published safety standard, or a named independent test — and the trace is printed on the page.

What this site is

An audit of the published evidence about tools. When two products are compared here, the comparison rests on figures their manufacturers publish, on what binding safety standards require, and on independent testing done by organizations and reviewers we name and link. The site's job is to gather those documents, read them carefully, put the numbers side by side, and walk through the arithmetic in the open.

What this site is not

A test lab, or a diary of shop experience. You will never read here that we put a tool through its paces, wore one out, or lived with one for a season, because those things did not happen. A review that invents first-hand experience is worthless to the reader and illegal for the writer — the FTC's rule on consumer reviews (16 CFR Part 465) prohibits reviews that misrepresent that the reviewer used a product. We comply the simple way: the voice of this site narrates documents, never hands.

The four evidence grades

Every load-bearing claim carries a stamped grade beside it, so you can see at a glance what kind of backing it has:

• Standard A binding safety standard: OSHA rule text, ANSI or IEC standards, CPSC data. The strongest grade — this is what the law or the standards body requires, linked to the rule itself.
• Spec A manufacturer-published figure: RPM, duty cycle, torque, amp-hours, from the maker's own spec sheet or manual. Reliable about the product's design; silent about how it holds up.
• Tested A named independent test, linked: who ran it, what they measured, how. We identify the tester and their method every time, so you can weigh the result yourself.
• Inference Our own arithmetic built from the grades above — rim-speed math, cost-per-watt-hour math, wattage sums — with the working shown so you can check it.

The sources ledger

Each guide ends with a numbered sources ledger. Every inline citation marker in the text keys to a numbered, linked entry there. If a claim has no marker, it is either common arithmetic you can verify on the page or it should not have shipped — tell us via the contact page and we will fix it.

What the evidence doesn't cover

Published evidence has gaps: some product classes have never had a rigorous cross-brand test, and spec sheets omit what manufacturers prefer not to measure. Every guide carries a standing section naming what the evidence does not cover, so you know where our sources end and your own judgment begins.

Independence

No affiliate links, no sponsored content, no review units, no payment from any manufacturer. Nothing about a purchase you make changes what this site earns, because it earns nothing from your purchases.

Corrections

When a source is updated, a standard revised, or an error found, the affected guide is revised and carries a dated change note. Guides here are maintained documents, and they say so.