← AskMachinist · Guides · Calculator · 🔎 Search

Star Knob Dimensions (DIN 6336, 32 to 80 mm)

Guide · Updated October 28, 2026

DIN 6336 covers star (lobe) knobs for jigs, fixtures and machines, knob diameter 32 to 80 mm, thread M6 to M16, Forms A to E. Every value below agrees across the JW Winco DIN 6336 catalog sheet and the Elesa DIN 6336 catalog, with knob diameter, thread and hub diameter also matching the Wegertseder DIN 6336 sheet. Skipped: total height h1, thread depth t2, Form A blank heights and weights, because sources conflict or only one source lists them. Check the current edition or your supplier for critical work.

Need an exact reference size?

Build any gage block stack with the free Gage Block Calculator. Free, no login.

Step by step

Pick the knob size: Choose knob diameter d1 from 32 to 80 mm. Bigger knobs give more torque by hand.
Match the thread: Each size takes one or two threads, for example 50 mm fits M8 or M10.
Pick the form: Form A is a raw blank, B a pilot hole, C an H7 reamed blind bore, D a tapped through bore, E a tapped blind bore.
Check the hub: Hub diameter d4 must clear nearby parts; minimum hub height h2 sets how far the knob stands off.
Check bore depth: On blind-bore forms, minimum depth t1 tells you the longest stud you can thread in.
Order it: Designate as DIN 6336 D 50 M10 (form, knob diameter, thread).

DIN 6336 star knob dimensions (mm)

Columns: knob diameter d1, thread d2 (Forms D and E; Forms B and C use the matching bore), hub diameter d4, minimum hub height h2 (Forms B to E) and minimum blind bore depth t1 (Forms C and E), as lettered in the JW Winco and Elesa sheets.

d1 | Thread d2 | d4 | h2 min | t1 min
32 | M6 | 12 | 9 | 12
40 | M8 | 14 | 12 | 15
50 | M8, M10 | 18 | 15 | 18
63 | M10, M12 | 20 | 19 | 22
80 | M12, M16 | 25 | 23 | 28

Worked example: 50 mm knob on an M10 stud

DIN 6336 E 50 M10 has an 18 mm hub at least 15 mm tall and a blind thread at least 18 mm deep. Cut the stud so it stops short of the bottom of the bore, or pick Form D so it can pass through.

Forms A to E

A: unmachined blank, finish it yourself.
B: pilot hole for your own bore.
C: H7 reamed blind bore for a pinned shaft.
D: tapped through bore.
E: tapped blind bore.

Common problems

Knob bottoms out on the stud: stud is longer than t1 on a blind bore; shorten it or use Form D.
Knob loosens: add thread locker or a set pin through the hub.
Too little grip: step up one knob size; the thread pairings overlap at 50, 63 and 80 mm.

FAQ

What is a DIN 6336 star knob?

A five-lobe hand knob for jigs, fixtures and machine adjustments, usually cast iron, also stainless steel, aluminum and plastic.

Which thread goes with which knob?

32 mm: M6. 40 mm: M8. 50 mm: M8 or M10. 63 mm: M10 or M12. 80 mm: M12 or M16.

Form D vs Form E?

Form D has a tapped through bore so a long stud can pass through. Form E has a tapped blind bore with a closed top.

Why is total height h1 missing?

Catalogs disagree on total height (20, 25, 32, 40, 50 mm vs 21, 26, 34, 42, 52 mm) and on thread depth t2 at 40 mm (12 vs 13 mm), so we left those out rather than guess.

Star knob vs tommy screw?

A star knob threads onto your own stud; a DIN 6304 tommy screw is a one-piece screw with a bar handle.

Related guides and calculators

Build your stack in seconds

The free Gage Block Calculator finds the fewest-block combination for inch and metric sets, with wear blocks. No login.

Questions? Ask a machinist.

General shop information only — follow your drawing, tool maker's data and your quality system.