RS PRO Black 4-Arm Clamping Knob, M8, Threaded Stud

View all Clamping Knobs
Bulk discount available

Subtotal (1 pack of 10 units)*

£37.99

(exc. VAT)

£45.59

(inc. VAT)

Add to Basket
Select or type quantity
In Stock
  • 11 unit(s) ready to ship
  • Plus 8 unit(s) ready to ship from another location
  • Plus 999,999,988 unit(s) shipping from 12 November 2025
Need more? Click ‘Check delivery dates’ to find extra stock and lead times.
Pack(s)
Per Pack
Per unit*
1 - 4£37.99£3.799
5 - 9£36.07£3.607
10 - 29£34.20£3.42
30 +£31.93£3.193

*price indicative

RS Stock No.:
686-648
Distrelec Article No.:
304-18-855
Brand:
RS PRO
Find similar products by selecting one or more attributes.
Select all

Brand

RS PRO

Thread

M8

Thread Diameter

8mm

Thread Length

25mm

Knob Shape

4-Arm

Mounting Type

Threaded Stud

Knob Diameter

50mm

Insert Material

Alloy

Colour

Black

COO (Country of Origin):
CN

RS PRO Phenolic Star Male Handwheel Knobs


Knobs are used in a wide variety of applications in our day-to-day lives and perform many functions, from being used as fixed handles to being used to tighten, loosen, adjust, clamp and push other components or pieces of equipment. They are used in various applications, from industrial and construction machinery to audio and visual equipment.


These star shaped handwheels – also known as multiple lobed handwheels– provide an easy-to-grip shape. This variation features four lobes, but other models will have varying numbers depending on the grip and pressure required. The knobs are fitted with a protruding screw insert (male) made from a combination of wood-filled impact-resistant thermoplastic bodies and zinc-plated steel inserts. Zinc-plated steel provides wear resistance for the threads to ensure that the threads last throughout general use and are not easily damaged or sheared.


Male knobs: M6 x 13mm (RS 686604), M6 x 25mm (RS 686610), M6 x 40mm (RS 686626), M8 x 20mm (RS 686632), M8 x 25mm (RS 686648), M8 x 40mm (RS 686654).


Features & Benefits


  • Wood-filled phenolic knobs

  • Zinc-plated steel threaded studs

  • Made to BS771 standards

  • Working temperature range of -30°C to +140°C

  • Tolerant of weak acids, with excellent resistance to chlorinated hydrocarbons

Applications


These star-shaped handwheel knobs are used in a variety of applications, with the shape providing an ergonomic grip for user comfort and added torque to be applied by hand. They are commonly used as fixing or fastening solutions in a variety of industries, including:


  • Access doors

  • Drawers & panels (domestic and industrial)

  • Clamps and fixtures

  • Machinery

Related links