Every magnetic drill gets a score from 0 to 100% built from five factors, which maps onto the 5-point rating shown on the site (a 0% score would be 1.5 stars; a perfect score, 5). Each factor is scored against fixed reference points, not against the other products in the list, so adding a new model never moves another model’s rating. Drills are grouped by largest cutter (up to 1 5/8 in, and 2 in and larger), and cutter size has its own scale for each group.
| Factor | Measures | Weight |
|---|---|---|
| Value | price per inch of largest cutter | 30% |
| Cutter size | largest annular cutter diameter | 20% |
| Power | motor power | 20% |
| Magnet | stated magnet holding force | 15% |
| Weight | lighter is easier to carry up a beam | 15% |
Where the numbers come from
Cutter size, motor power, speed, stroke, weight and warranty come from the maker’s product page or spec sheet. For budget brands that publish no spec sheet, they come from the Amazon listing. Prices are checked at Amazon, and the lowest price at a store the page links to is used.
The factors
Value is the current price divided by the largest cutter in inches, on a log scale, so going from $800 to $400 per inch counts as much as going from $400 to $200. $1,800 per inch scores zero and $100 full marks.
Cutter size is the largest annular cutter diameter the maker rates the drill for. Up to 1 5/8 in, 1 in scores zero and 1 5/8 in full marks; for 2 in and larger, 1 3/4 in and 2 1/2 in.
Power is the motor’s rated watts, from 800 W (zero) to 1,700 W (full marks). When only amps are printed, watts are taken at 120 V and marked as estimated.
Magnet is the maker’s stated holding force, from 1,000 lbf (zero) to 3,000 lbf (full marks). Makers measure it differently, so this factor is weighted lightly, and the product page says how each figure was measured.
Weight is the machine weight, from 60 lb (zero) to 20 lb (full marks). A lighter drill is easier to carry up a structure.
What isn’t scored
Cutting depth, stroke, twist drill capacity, speed, reverse and warranty are listed but not scored. Warranty is shown because it often decides the choice between a budget and a name-brand machine.
Missing data
If a figure isn’t published, that factor gets the neutral middle score (50) and the product page marks it as estimated. Several makers do not publish magnet force or weight.
Ties and discontinued models
Products are ranked by score within each group. Discontinued models stay listed but rank below every current model and can be hidden with the “Hide discontinued” filter.