Thumb Screws & Knurled Screws
Knurled thumb screws for tool-free adjustment, in steel, stainless and brass.
Thumb screws for adjustments made by hand, with the knurl cut deep enough to grip with oily fingers. Straight knurl for grip, diamond where the hand is dry.
How we make it: Swiss CNC machining service →
2–4 weeks
500 pieces
ISO 9001:2015
Technical Specifications
| Parameter | Value | Unit |
|---|---|---|
| Thread range | M3–M12 | metric |
| Knurl type | Straight · diamond | - |
| Head diameter | ±0.15 | mm |
| Head thickness | ±0.1 | mm |
| Torque by hand | Limited | note |
| Non-metallic option | Nylon / POM | available |
Available Materials
- Stainless 303
- Brass C360
- Steel 12L14
- Aluminium 6061
- Nylon (light duty)
Typical Applications
- Instrument adjustment
- Machine setting screws
- Camera and optical mounts
- Panel fasteners
- Clamping knobs
Surface Finishes
- Passivate
- Nickel plating
- Black oxide
- Brass natural
- Anodise
Industries Served
- Instrumentation
- Industrial Equipment
- Consumer Electronics
- Medical
- Aerospace
What drives the price of this part
Derived from the callouts on this page. Where a driver is not on the drawing, it is not on this list.
- Part size
- Thread range at M3–M12 metric decides which machine the part lands on and how many setups it needs. Size is the driver buyers most often leave out of a first enquiry, and it is the one that changes the quote fastest.
- Material
- The first material listed, Stainless Steel 303, rates 6/10 on our machinability scale at 228 HB. On this shop's scale a harder alloy means slower passes and more tool changes, and that is cycle time the quote has to carry.
- Order size
- Minimum order is 500 pieces, where setup and tooling are amortised across the batch and per-part cost settles around cycle time and material. Below that quantity the same part costs more per piece, not less.
See how cycle time is calculated in the machining time calculator and what else moves a price in the cost driver reference.
How these parts are inspected
Matched to the callouts above and the instruments actually on the floor.
- Coordinate measuring machine (Zeiss CONTURA G2, two machines, GR&R 8.4% on the critical feature)
- Dimensional report against the drawing, with a 100% check on critical features rather than a sample
- Certificate of conformance and the mill certificate with every shipment
- Thread gauges over the full thread range on the drawing
The full equipment list, with counts, is on the capability page; the inspection sequence is on quality and inspection.
Questions buyers ask
- How much torque can a thumb screw take?
- Only what a hand can apply, and the knurl is what decides it. If the joint needs more than light clamping, use a socket head with a torque spec instead.
Related part families
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Cup, cone, flat and dog point set screws to DIN 913–916 with knurled or hex sockets.
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Dome and acorn nuts that cover the thread end, for safety and finish.
Socket Head Cap Screws
12.9 socket caps to DIN 912 / ISO 4762, machined for special lengths and materials.