Key takeaways
- The numbers on the clutch ring are positions, not newton metres or inch pounds. Festool's manual says it plainly. Position 1 is low torque, position 12 is high torque, and the drill symbol is maximum torque.
- Higher numbers do mean more torque. Halfway round the ring does not mean half the max torque, because the clutch range is a small part of that figure. Metabo's BS 18 LT clutch runs 0.7 to 8 Nm, against 60 Nm hard joint.
- Across five drills whose makers print both figures, the top of the clutch range is 13 to 27 percent of the hard joint max, and 6 percent in Festool's fast gear. The rest of the max is only reached in the drill position, where the clutch does not slip.
- The gear changes the scale. Festool's TXS 18 and CXS 18 clutch runs 1.1 to 8 Nm in 1st gear and 0.4 to 2.3 Nm in 2nd, so the same number gives about a quarter of the torque in the fast gear.
- Bosch, Milwaukee, Makita and DeWalt print no clutch range on the pages checked here, and no maker prints a tolerance for any position. When a fastener has a torque spec, use a torque wrench.
Two readings of the ring go around. One says the numbers are just steps and mean nothing, while the other treats them as a scale of the drill's full power, so setting 10 of 20 is half the max torque. The first is too gloomy and the second is wrong. The numbers do rank torque, low to high, but they rank it inside a narrow band at the bottom of what the drill can do. Below, drills from seven makers go on one scale, and one is worked through at the middle of its ring.
What a drill clutch is
A drill's clutch is the part that stops the drill turning a screw once the screw resists hard enough. The ring behind the chuck sets how hard that is. When the screw needs more twist than the setting allows, the clutch slips with a ratcheting click and the chuck stops driving, even though the motor can keep running. Bosch describes its electronic version on the GSR 18V-90 C as a clutch that stops rotation "once a preset torque level is achieved."
Torque is turning force, meaning how hard the drill twists the bit, and it is given in newton metres (Nm) or inch pounds (in-lb). One Nm is about 8.85 in-lb.
The clutch numbers are the positions on that ring. Festool's manual for its 10.8 V CXS states what they are: "Position 1 = low torque" and "Position 12 = high torque". Nothing on the ring says how many Nm any position is, so they are steps, like the notches on a volume knob.
The drill position is the extra mark past the top number, usually a drill bit symbol, and in that position the clutch does not slip at all. Festool's manual says the drill symbol set to the arrow gives "maximum torque."
Max torque is the big number on the box or the spec page, and most makers print two. Metabo, Bosch and Hilti call them soft and hard, while Festool's catalog lists the same pair as wood and steel. A soft joint is one where the resistance builds slowly as the screw goes in, like a screw in wood. A hard joint is one where it stops short, like a bolt seating on steel. On every drill here the hard figure is the larger one.
The two scales on one drill
Take the Metabo BS 18 LT, because Metabo prints both scales on one page.
| What Metabo prints | Figure | In in-lb |
|---|---|---|
| Maximum torque, soft | 34 Nm | 301 in-lb |
| Maximum torque, hard | 60 Nm | 531 in-lb |
| Adjustable torque | 0.7 to 8 Nm | 6 to 71 in-lb |
The adjustable torque line is the clutch range, the span from the lowest number on the ring to the highest. The max torque lines are what the drill can deliver in the drill position, with the clutch out of the way.
Do the division:
8 Nm / 60 Nm = 0.133, or 13 percent
8 Nm / 34 Nm = 0.235, or 24 percent
So the very top of the clutch is about one seventh of the hard joint figure and under a quarter of the soft one. Everything above 8 Nm is drilling torque, and no position on the ring gives it to you while the clutch is working.
Why "half the ring is half the torque" keeps going around
The ring looks like a dial, and dials usually run from zero to full. Many spec pages make it worse by printing one torque figure and no clutch range at all, so the buyer sees "60 Nm" and a ring numbered 1 to 20, and joins them up.
The pages checked for this article show how common that gap is:
- Bosch prints 36/64 Nm soft and hard and "Torque settings: 21" for the GSR 18V-90 C, but no torque for any setting.
- Milwaukee prints "1400 in-lbs of torque" for the M18 FUEL 2903-20 and a "Mechanical Clutch", with no count of positions and no range.
- Makita prints 530 in-lb (60 N·m) for the XFD12Z and mentions "adjustable torque settings", again with no count and no range.
- DeWalt's DCD800B page gives no torque figure at all. It lists speed, up to 2,000 rpm, and a power claim against an older model.
With nothing else on the page, the one torque number gets read as the top of the ring. So to settle it: the higher the number, the more torque, yes; halfway round the ring is half the max, no.
Seven makers, both scales
Where makers print both figures, here is what they say. The last two columns are this site's arithmetic, not the makers'.
| Maker, model | Max torque, soft / hard | Clutch range | Positions printed | Average step | Top of clutch as share of hard max |
|---|---|---|---|---|---|
| Metabo BS 18 LT | 34 / 60 Nm | 0.7 to 8 Nm | Not on the page | Not computable | 13% |
| Hilti Nuron SF 4-22 | 36 / 62 Nm | 1.5 to 10 Nm | 15 | 0.61 to 0.65 Nm | 16% |
| Festool CXS (10.8 V) | 10 / 16 Nm | 0.2 to 2.4 Nm | 12, plus drill | 0.20 Nm | 15% |
| Festool TXS 18, CXS 18, 1st gear | 22 / 40 Nm | 1.1 to 8 Nm | 13 | 0.58 to 0.63 Nm | 20% |
| Festool TXS 18, CXS 18, 2nd gear | 22 / 40 Nm | 0.4 to 2.3 Nm | 13 | 0.16 to 0.17 Nm | 6% |
| Festool TPC 18/4, 1st and 2nd gear | 50 / 75 Nm | 2 to 20 Nm | Not fetched | Not computable | 27% |
| Bosch GSR 18V-90 C | 36 / 64 Nm | Not printed | 21 | Not computable | Not computable |
| Milwaukee 2903-20 | 1,400 in-lb (one figure) | Not printed | Not printed | Not computable | Not computable |
| Makita XFD12Z | 530 in-lb, 60 N·m (one figure) | Not printed | Not printed | Not computable | Not computable |
| DeWalt DCD800B | No torque figure | Not printed | Not printed | Not computable | Not computable |
How the two derived columns are worked:
Average step is the clutch range divided by the gaps between positions: (top - bottom) / (positions - 1). It assumes the positions are evenly spaced, which no maker says they are. Where a maker's count might include the drill position, the column gives both answers. Festool's older CXS manual counts 12 numbered positions and a drill symbol, so its retail "13 torque settings" on the CXS 18 may be 12 plus drill. For the CXS 18 in 1st gear that gives 6.9 / 12 = 0.58 Nm if all 13 are clutch positions, or 6.9 / 11 = 0.63 Nm if one is the drill mark. Hilti's 15 is handled the same way: 8.5 / 14 = 0.61 Nm or 8.5 / 13 = 0.65 Nm.
Share of hard max is the top of the clutch range divided by the hard joint figure. On the Festool TPC 18/4 that is 20 / 75 = 0.27. On the CXS 18 in 2nd gear it is 2.3 / 40 = 0.06.
Across the five drills that print both, the top of the clutch range sits at 13 to 27 percent of the hard joint max. In Festool's fast gear it is 6 percent. Not one gets near half.
Hilti shows why the manual is worth a look. Its product page gives only the 36/62 Nm pair and "torque increments 15". The SF 4-22 operating instructions print the range as well: 1.5 to 10 Nm.
Worked through: the middle of a 15-step ring
Take the Hilti SF 4-22 and suppose the ring is set to 8, the middle of 15.
The halfway reading. Eight of fifteen is about half, and half of 62 Nm is 31 Nm (274 in-lb).
What the published figures allow. The clutch range tops out at 10 Nm (89 in-lb), so position 8 cannot be 31 Nm, because no position reaches even a third of that.
Where position 8 likely sits. If the 15 positions are evenly spaced from 1.5 Nm, position 8 is seven steps up:
1.5 + 7 x 0.61 = 5.8 Nm
If one of the 15 is the drill mark, the step is 0.65 Nm:
1.5 + 7 x 0.65 = 6.1 Nm
So position 8 is about 6 Nm, or roughly 51 to 54 in-lb. That is about a fifth of the 31 Nm the halfway reading predicts. The even spacing is an assumption, but the ceiling of 10 Nm is not: it comes straight from Hilti's manual.
Now take the same idea to a drill that prints only a max. Say a Bosch GSR 18V-90 C is set to 10 of its 21 settings. Half of 64 Nm would be 32 Nm. Bosch does not print a clutch range, so the true figure cannot be worked out. All the page supports is that 10 gives more torque than 9 and less than 11. The 32 Nm reading has nothing behind it.
The gear changes the scale
Festool prints a separate clutch range for each gear on the TXS 18 and CXS 18:
| Gear | Clutch range | In in-lb |
|---|---|---|
| 1st gear | 1.1 to 8 Nm | 9.7 to 70.8 in-lb |
| 2nd gear | 0.4 to 2.3 Nm | 3.5 to 20.4 in-lb |
The ring and its numbers are the same, but the top position slips at 8 Nm in 1st gear and at 2.3 Nm in 2nd. That is 8 / 2.3 = 3.5 times as much in the slow gear. Festool's older 10.8 V CXS lists 1st gear at 0 to 400 rpm and 2nd at 0 to 1,200 rpm, so on that drill 1st is the slow gear.
So a number that seats a screw in 1st gear may stop well short in 2nd. If a screw stalls in the fast gear, try the slow gear at the same number before turning the ring up.
Festool's TPC 18/4 is printed the other way: one range, 2 to 20 Nm, for 1st and 2nd gear together. The other makers here print no per-gear figure, so this page cannot say whether their clutch ranges shift with the gear.
Picking a number when none is printed
The numbers are relative, so pick one the way the ring is built to be used:
- Start low. On a 15 to 21 step ring, a low single figure is a sensible place to begin for small screws.
- Drive a test screw into scrap of the same material, or into the job where a spare hole does no harm.
- If the clutch slips before the head seats, go up one or two numbers and try again.
- Stop at the first number that seats the head flush. Use that number for the rest of the batch.
- Keep the drill position for drilling.
Festool's screwdriving guide names the usual cause of overdriven or snapped screws: "mistakenly using maximum torque for screwdriving." The drill symbol is that maximum.
This test is how the numbers become useful. Once you know that 6 seats a cabinet screw in your wood with your drill, 6 means something, though it still means nothing in Nm. Our garage wall cabinet screw guide explains why a screw driven past seated in a softwood stud loses its hold.
When the torque actually matters
A clutch number is fine for a cabinet hinge, but it is the wrong tool for a fastener with a printed torque spec.
The reason is the tolerance. A click torque wrench rated to ±4 percent tells you how far from the setting it may be, as set out in what ±4% accuracy means on a torque wrench. None of the drill pages or manuals checked here gives any tolerance for any clutch position. With no tolerance, a reading of "position 6" is not a torque. The same holds for impact tools, whose box figures are not tightening specs either, as shown in nut-busting vs fastening torque.
Drive the fastener snug with the clutch set low, then finish it to spec with a torque wrench. Store that wrench as its maker asks, covered in whether to store a torque wrench at zero, so its number stays true.
Comparing the max torque between brands
The headline figure is still worth something, since it tells you how hard a drill can twist in the drill position, which matters for large bits and hole saws. Read it with care across brands, though.
Metabo prints 60 Nm as its hard joint figure. Makita prints 60 N·m as a single figure. Milwaukee prints one figure, 1,400 in-lb, which is about 158 Nm (1,400 x 0.113), with no soft or hard label. DeWalt's page prints none. A one-figure rating and a soft and hard pair are not the same kind of number. Battery naming has the same problem, worked through in whether 20V MAX is the same as 18V.
Where this answer stops applying
- No maker prints a tolerance per position. On every page and manual checked here, the clutch range is two end figures and nothing in between. The average step in the table is arithmetic on those ends, assuming even spacing.
- Four of the big US makers print no clutch range. On the pages checked, Bosch, Milwaukee, Makita and DeWalt give no clutch range. A manual not checked here may print one. Until you find it, treat the numbers on those drills as steps with no unit.
- The gear can move the range. Festool shows that it does on the TXS 18 and CXS 18. Other makers do not say either way.
- Electronic clutches. Bosch's Precision Clutch stops rotation electronically. Bosch prints no range for it, so this page does not say how its settings map to torque.
- The tool's condition. These are the makers' ratings for tools as sold. Nothing here covers a clutch that is worn, dirty or damaged.
- Published figures only. Nobody tested a drill for this page. Every figure comes from a maker's page, catalog or manual, and every derived figure has its working shown beside it.
The thirty-second check
- Treat the clutch numbers as steps. Higher means more torque, but no number is in Nm or in-lb.
- Look for the "adjustable torque" or "torque setting" line on the spec sheet. That is the clutch range. The big soft and hard figures are for drilling.
- Divide the top of the clutch range by the hard max. On the five drills here that is 13 to 27 percent, so halfway round the ring is a small fraction of the box figure.
- Check the gear. On Festool's TXS 18 and CXS 18 the top position is 8 Nm in 1st gear and 2.3 Nm in 2nd.
- For anything with a torque spec, finish with a torque wrench.