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Ball knobs, DIN 319 (plastic), Ø16–50: thread M4–M12, neck diameter d4, height h and thread depth
What are the dimensions of a DIN 319 ball knob, and which thread does a Ø25 or Ø40 ball knob have? · Standard part · basis: Halder's DIN 319 ball knob catalog page (form C with moulded thread and form E with threaded bush, Ø16 to 50); Ganter's DIN 319 datasheet as a cross-check; numbers only
Also called: DIN 319 ball knob, Kugelknopf DIN 319, ball knob M6, 25 mm ball knob thread, ball knob dimensions, round knob M8 40 mm, DIN319 C, ball knob height
Exact dimensions. Every file is drawn at true size with no tolerance added. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your process's clearance before making the part. Mating features
- sizes
- 6 in table
Notes
- Halder's table (plastic ball knobs, mm): d1 ball diameter, d2 thread, d4 ≈ and h ≈ (both marked approximate on the page) and the minimum thread depth, t1 for form C (moulded-in thread) and t2 for form E (threaded bush); the page does not define t1, t2 or d4 in text. The page lists each size in black and in red with identical dimensions, so one row per size is shown. The Ø16 form E has a brass bush (page footnote). Only 24 of the page's 30 listed rows were read, and form M (taper bore) did not appear in them, so those variants are not covered.
- Ganter's DIN 319 datasheet sample rows (Ø16 with M4, Ø20 M5, Ø25 M6, Ø32 M8, Ø40 M10) show d4 8, 12, 15, 18, 22 and h 15, 18, 22.5, 29, 37, which match the Halder figures; the datasheet text has more values per row than headers, so its depth columns are not used and the Halder depth figures are the ones shown. Ganter's page also lists steel, aluminum and stainless ball knobs, and says these are 'not on the official DIN standard sheet'. Types there: C tapped hole, E tapped bush, K plain hole H7, L tolerance ring (press-on), M tapped bore (press-on).
- DIN 319 is a ball knob; the DIN 6336 star knob and DIN 39 fixed handle are separate pages. No file: the ball is a sphere of Ø d1 with a flat and a neck whose profile is not given as numbers in the sources read (d4 and h are approximate). McMaster-Carr sells threaded ball knobs with per-part STEP; linked, not copied.
Ball knobs, DIN 319 (plastic), Ø16–50: thread M4–M12, neck diameter… size chart
| d1 (ball Ø) | d2 thread | d4 ≈ | h ≈ | t1 min (form C) | t2 min (form E) |
|---|---|---|---|---|---|
| 16 | M4 | ~8 | ~15 | 7 | 6 |
| 20 | M5 | ~12 | ~18 | 9 | 7.5 |
| 25 | M6 | ~15 | ~22.5 | 11 | 9 |
| 32 | M8 | ~18 | ~29 | 14 | 12 |
| 40 | M10 | ~22 | ~37 | 18 | 15 |
| 50 | M12 | ~28 | ~46 | 21 | 18 |
Mating features
Drawn at the exact size. Open press, slide, run and socket features by your process's clearance (tolerances by process); leave designed gaps and clamp fits as drawn.
| feature | exact | mates with | fit | files |
|---|---|---|---|---|
| thread d2 | M4 (Ø16), M5 (Ø20), M6 (Ø25), M8 (Ø32), M10 (Ø40), M12 (Ø50), minimum thread depth t1 / t2 per table | stud or screw of the same metric thread | designed | all |
Where the files are
Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.
| Halder | DIN 319 ball knobs (plastic), form C (moulded thread) and form E (threaded bush): d1, d2, d4 ≈, h ≈, t1 / t2 min; Ø16 to 50 (24 of 30 listed rows read) | web | Maker catalog page; numbers only. d4 and h are approximate (~) on the page |
| Elesa+Ganter | DIN 319 ball knobs datasheet (types C, E, K, L, M; KU / KT / ST / AL / NI): sample rows d1, d2, d3, d4, h, t1, t2 | web | Maker datasheet; used as a cross-check only (column alignment unclear in the text) |
| McMaster-Carr | Metric ball knobs (free STEP/IGES per part, for your own design use; no redistribution) | STEP, IGES, PDF | McMaster-Carr site terms: personal design use, no redistribution verify |
| McMaster-Carr | Threaded ball knobs (free STEP/IGES per part, for your own design use; no redistribution) | STEP, IGES, PDF | McMaster-Carr site terms: personal design use, no redistribution verify |
Xem scan
File coming
No downloadable true-size file yet: the published figures do not fix the whole shape, and Xem never guesses a number. A measured scan is planned; request it and it moves up.
https://xemstudio.com/mcp to Claude, ChatGPT, Cursor or any MCP client (free, no account, one minute) and it can look up exact sizes, mating fits and free STEP/STL from every chat.Plain text: sheet.txt · JSON: /api/geometry?object=ball-knobs-din-319
Fits with
Questions
What thread does a 25 mm DIN 319 ball knob have?
M6 (form C or E), with d4 ≈ 15, h ≈ 22.5 and minimum thread depth 11 mm (form C) or 9 mm (form E) on Halder's page.
What is the difference between form C and form E?
Form C has a thread moulded into the knob; form E has a threaded bush (Halder).
How tall is a Ø40 ball knob?
About 37 mm (h ≈ 37), with an M10 thread and d4 ≈ 22.