A clamping knob puts a hand where a spanner would be: the form of the head decides how much torque the hand can give and how comfortably, and the stud or tapped hole decides what it fits. DIN 6336 and 6335 fix the star forms, DIN 6337 the ball, and the makers fix the lobe knobs and levers. A stud of another length, a fine or inch thread, a stainless head or a lever that must clear a guard is a knob that gets made.
EKINSUN LTD is a custom parts manufacturer that makes clamping knobs, knob nuts and levers to drawing: a stud turned to your length in 304 or 316L, a fine or inch thread in a stock head, an all-stainless or aluminium head, a lever length that clears the machine, a brass insert in a phenolic knob. The form table below is read from a 2026 catalogue; the hand-torque table explains what each form gives; the negative-space table marks the border.
"Seven-lobe knobs with a 316 stud, M10 x 1.25, 60 mm long, for a washdown line. The stock stud is 25 mm, zinc."
Stud length and stud material: the two reasons a knob is made rather than bought.
| Form | Standard | Stock range | Stock head and stud materials | Notes |
|---|---|---|---|---|
| Star knob, tapped or with stud | DIN 6336 | M4–M12 | phenolic or nylon head; zinc or 304 stud / insert | five-point star; the classic machine knob |
| Star grip | DIN 6335 | on request | phenolic; cast | six-point, larger |
| Lobe knob screw, five-lobe | maker series | M6–M8; M8–M10 | black phenolic, white and yellow nylon; 304 stud | smaller than a star, rounder in the hand |
| Lobe knob screw, seven-lobe | maker series | M4–M12; 304 stud M2–M12 | phenolic; 304 | the most common lobe form |
| Lobe knob nut, five- and seven-lobe | maker series | M4–M12 | phenolic or nylon with brass or 304 insert; through or blind | — |
| All-stainless lobe knob | maker series | M6–M12 nut; M6–M8 screw | 304 head and stud | washdown, food, outdoor |
| Ball knob | DIN 6337 | M6–M16 | phenolic with brass or phenolic core | lever ends and shift handles |
| Adjustable clamping lever | maker series | M4–M16, internal or external thread | black die-cast zinc or plastic handle; steel or 304 stud | ratchets to any angle; the lever for guards and fixtures |
| Z-handle screw | maker series | M4–M8 | phenolic; 304; white-zinc steel | a flat handle for tight spaces |
| Wing knob / wing screw | DIN 316 form | M4–M16 | 304; steel | see wing nuts and wing screws |
| Knurled thumb screw, high and flat | DIN 464 / DIN 465 | M2–M10; M3–M10 | 304; nickel, black and zinc steel; brass | see thumb screws |
| Knurled thumb nut, high and flat | DIN 466 / DIN 467 | M3–M12 | 304; nickel, black and zinc steel | see knurled nuts |
| Chassis thumb screw | maker series | M3–M4 | nickel and zinc steel; 304 | computer and rack panels |
| Bakelite round and knurled thumb screws | maker series | M4–M6 | phenolic head, steel stud | instruments |
| Metal round thumb screw | maker series | M3–M8 | 304 | — |
| Form | Grip | Hand torque | Space needed | Best for |
|---|---|---|---|---|
| Star knob | fingers between points | high | a circle around the knob | machine tables, vices, tripods |
| Lobe knob | fingers on lobes | medium to high | a circle | guards, covers, adjustable stops |
| Ball knob | palm | low | small | lever ends, where the knob is pushed not turned |
| Adjustable lever | the whole hand on a lever | the highest | a swept arc; the lever can be re-indexed to clear obstacles | fixtures, saw fences, guards clamped hard |
| Z-handle | two fingers | medium | a flat arc | tight spaces between panels |
| Thumb screw, knurled | thumb and finger | low | very small | instruments, panels opened often |
| Wing knob | thumb and finger on wings | low to medium | a bar | light covers |
Read the pitch before you order the knob stud. Lay a steel rule along ten thread crests and divide by ten: 10 mm over ten pitches is a 1 mm pitch (M6 coarse), 12.5 mm is M8 coarse, 15 mm is M10 coarse, 17.5 mm is M12 coarse. A reading that is not a round number of millimetres is an inch thread, and a reading that is shorter than the coarse pitch for that diameter is a fine thread. If diameter, pitch and the size range in the table all agree, buy the stock part. If any of the three is off the shelf, that is the one we make. The full measuring routine, including the inch traps →
| What you need | In the catalogue? | What we make |
|---|---|---|
| Star knob DIN 6336 or lobe knob M4–M12 with a stock zinc or 304 stud, phenolic or nylon head | Yes | Buy it from stock. No one-off competes with a moulded knob on a stock stud. |
| Adjustable clamping lever M4–M16, ball knob DIN 6337 M6–M16, chassis thumb screw M3–M4 | Yes | Stocked; buy it. |
| A knob with a stud longer or shorter than stock, or in 316L, brass or titanium | No | Stud turned to length and material and fitted to a stock head, from 1 piece. |
| A knob nut or knob screw in a fine, left-hand or inch thread | No | Insert or stud threaded to your reading. |
| An all-metal knob or lever head in 304, 316L, brass or aluminium 6061 / 7075 | No | Machined from bar; polished or anodised. |
| A lever of a length or angle that clears your guard, or with a longer stud | No | Lever machined or sourced to length; stud turned. |
| A knob head in a colour, a size or a lobe count the series does not offer | Partly | Heads are moulded per batch above a minimum; below it the head is machined from nylon, POM or aluminium, and we say which. |
| A knob for a joint that must be torqued to a value | No | Not a knob job: we quote a bolt and the torque instead, and say why. |
| Material | Designation | Where it fits here |
|---|---|---|
| Phenolic (bakelite) | PF | stock star and lobe knob heads; heat and oil resistant |
| Nylon 66, POM | PA66, POM | stock coloured heads; machined heads to order |
| Zinc die-cast | ZnAl4 | stock lever handles |
| Carbon steel, zinc or nickel | low-carbon | stock studs and inserts |
| Stainless 304 | 1.4301 / A2 | stock stainless studs, all-stainless knobs, thumb screws |
| Stainless 316L | 1.4404 / A4 | turned studs and heads for washdown and marine |
| Free-machining stainless | 303 / 1.4305 | machined knob heads and studs |
| Brass | CW614N / C36000 | inserts in knob nuts; decorative thumb screws |
| Aluminium 6061 | AlMg1SiCu | machined light knob heads, anodised |
| Aluminium 7075 | AlZn5.5MgCu | machined knob heads and levers where a light head must take more torque |
A star knob (DIN 6336) has five sharp points that the fingers sit between and gives the most hand torque; a lobe knob has five or seven rounded lobes, is smaller and kinder to the hand, and is the common choice for guards and covers. Both come as knob screws with a stud or knob nuts with a tapped insert.
The handle sits on a serrated ring over the threaded stud or nut; lifting the handle disengages the serrations so it can be turned to a new angle, and releasing it re-engages. It gives the highest hand torque of any knob and can always be parked clear of an obstacle.
Stock covers 304 studs on phenolic heads, all-304 lobe knobs M6–M12, and 304 thumb screws. 316L studs and heads, and stainless levers, are made to order.
Yes. Studs and inserts are turned in 304, 316L, brass or steel to any length and thread, fitted to a stock or machined head, from 1 piece.
EKINSUN LTD is a custom parts manufacturer that makes clamping knobs, knob nuts, thumb screws and levers with studs, inserts and heads machined to drawing in stainless, steel, brass, aluminium, nylon and POM, from 1 piece, with a quote within 12 hours.
No list price; the drivers are the stud (turned or stock), the head (moulded, machined or stock) and quantity. A stock lobe head on a 316L stud turned to length is close to catalogue money; an all-stainless machined star knob is priced as the machined part it is. The quote separates head and stud.
Knob form, thread and pitch, stud length or tapped depth, head material and colour, stud material, quantity. A photo of the fixture works. From 1 piece, quote within 12 hours.
Knobs, knob nuts and levers made to stud length, thread, head and material — from 1 piece, quote in 12 hours.