The shaft sets the section
Shafts over 30 up to 38 mm take a 10 × 8 key, over 38 up to 44 a 12 × 8. A boundary belongs to the smaller range: a 30 mm shaft takes 8 × 7.
Reference tool — not a drawing
Find the key before it goes in an RFQ.
Parallel key
Shaft, key, keyways, length.
Enter the shaft diameter or the measured key. Below the examples, the size of an offered key can be checked against it: width, height and length. The drawing and the RFQ line update with every change.
Examples:
Replacement check
On the sizes alone: the form (A or B), the material and the fit are checked separately.
All 130 engineering tools
A parallel key is ordered by its width, height, length and form. In DIN 6885-1 the shaft diameter sets the key section and the keyway depths, so one shaft measurement names the key — or an old key names the shaft. Enter the diameter or the measurement, and the finder shows the key and keyways to scale and writes the RFQ line.
The hub keyway depth t2 is the loose-fit value, the table’s nominal. A key that matches no row may be an inch size or a special.
How a key is read
Section, keyways, length.
Keyways in shaft and hub
A 10 × 8 key sits 5 mm in the shaft (t1) and 3.3 mm in the hub (t2). The keyway is as wide as the key.
The length from the series
Lengths run 6, 8, 10 … 400 mm. For an old key of 47 mm, the nearest lengths of the series are 45 and 50 mm.
| b × h, mm | Shaft over–to, mm | Shaft t1, mm | Hub t2, mm |
|---|---|---|---|
| 2 × 2 | 6–8 | 1.2 | 1 |
| 3 × 3 | 8–10 | 1.8 | 1.4 |
| 4 × 4 | 10–12 | 2.5 | 1.8 |
| 5 × 5 | 12–17 | 3 | 2.3 |
| 6 × 6 | 17–22 | 3.5 | 2.8 |
| 8 × 7 | 22–30 | 4 | 3.3 |
| 10 × 8 | 30–38 | 5 | 3.3 |
| 12 × 8 | 38–44 | 5 | 3.3 |
| 14 × 9 | 44–50 | 5.5 | 3.8 |
| 16 × 10 | 50–58 | 6 | 4.3 |
| 18 × 11 | 58–65 | 7 | 4.4 |
| 20 × 12 | 65–75 | 7.5 | 4.9 |
| 22 × 14 | 75–85 | 9 | 5.4 |
| 25 × 14 | 85–95 | 9 | 5.4 |
| 28 × 16 | 95–110 | 10 | 6.4 |
| 32 × 18 | 110–130 | 11 | 7.4 |
| 36 × 20 | 130–150 | 12 | 8.4 |
| 40 × 22 | 150–170 | 13 | 9.4 |
| 45 × 25 | 170–200 | 15 | 10.4 |
| 50 × 28 | 200–230 | 17 | 11.4 |
| 56 × 32 | 230–260 | 20 | 12.4 |
| 63 × 32 | 260–290 | 20 | 12.4 |
| 70 × 36 | 290–330 | 22 | 14.4 |
| 80 × 40 | 330–380 | 25 | 15.4 |
| 90 × 45 | 380–440 | 28 | 17.4 |
| 100 × 50 | 440–500 | 31 | 19.5 |
The hub keyway depth t2 is for a loose fit. Lengths: 6, 8, 10, 12, 14, 16, 18, 20, 22, 25, 28, 32, 36, 40, 45, 50, 56, 63, 70, 80, 90, 100, 110, 125, 140, 160, 180, 200, 220, 250, 280, 315, 355, 400 mm.
Sources
The DIN 6885-1 table — key sections by shaft range, keyway depths t1 and t2 and the length series — as reproduced by fasten.it and by globalfastener (DIN 6885 (B), 1968; a 2021 edition of DIN 6885-1 is listed); the two agree row by row.
Before you send the key
Questions about keys in an RFQ
Which key does a 35 mm shaft take?
In DIN 6885-1, shafts over 30 up to 38 mm take a 10 × 8 key: 10 mm wide, 8 mm high, in a keyway 5 mm deep in the shaft and 3.3 mm in the hub. At exactly 30 mm the shaft is still in the 22 to 30 range and takes 8 × 7.
How do I identify an old key?
Measure its width and height with a caliper: the width names the key in almost every size, and the height settles the few widths that share a shaft range. Give the length too; the series runs 6, 8, 10 … 400 mm.
What are form A and form B?
Form A has both ends rounded, for a keyway milled with an end mill; form B has square ends. Keep the form of the old key, or look at the ends of the keyway in the shaft.
What are t1 and t2?
The keyway depths: t1 in the shaft, t2 in the hub. A 10 × 8 key sits 5 mm in the shaft and 3.3 mm in the hub. Across the shaft, d - t1 checks the shaft keyway; over the hub bore, d + t2 checks the hub keyway.
Is DIN 6885 the only key standard?
No: inch shafts use inch keys, and some makers use their own keys. When a measured key matches no row of the table, it is likely an inch size or a special: send the measurements and a photograph.
Key found?
Send the line with the photographs.
A found line is a cross-check on the measurements, not proof. Attach photographs of the key and the keyway, and Vessel Core checks them against each other before an offer goes back.
Buyer tools
