Automotion Components is a leading manufacturer of precision shoulder fastenings. Our shoulder screws can be produced to customer drawings and we can offer a wide range of materials and finishing options. We hold a large volume of metric and imperial shoulder screws (and bolts) in stock which means that we can usually offer same-day shipping from our warehouse in the UK.
What are shoulder screws?
Shoulder screws have an additional unthreaded "shoulder" in between the head and the thread of the screw. The shoulder is a larger diameter than the thread and has a very low tolerance. This helps with the precise alignment of moving parts; the shoulder screw acts as both a fastener and a dowel/axel/guide.
Shoulder screw fastenings are exellent for applications with rotating or sliding elements. They are often used in the automotive industry to attach gears or wheels, in the medical tool manufacturing industry, and in injection molding applications (where the shoulder acts as a linear guide so that the two halves of the mold align correctly).
How to choose a shoulder screw
Shoulder screws have a head, thread, and smooth shoulder that are manufactured to tight tolerances. We stock a large range of the most popular sizes, but as a precision shoulder screw manufacturer, we are ready to help your designs come to life with custom components.
- The first thing to think about when choosing a shoulder screw is the material choice. As standard, we stock steel (grades 8.8, 10.9 and 12.9) and stainless steel (AISI series 303 (A2), 316 (A4) and martensitic series 416) shoulder screws.
- Next, select the shoulder diameter (and then length). This will be dependent on your application.
- Select the thread size that you require. Some of our products come with a long thread length option as standard, but please enquire if you need other options.
- Consider head height - would your application benefit from a low head-height shoulder screw?
- Choose a drive style. We can make many different styles, but our most popular include: hex drive, hex bolt, TX drive, Phillips drive.
- Finishing options: do you require zinc plating (for an anti-corrosion layer over steel) or a blackened finish?
You might find our product selection chart helpful to quickly see the differences between some of our popular shoulder screws. See our full range of shoulder fastenings here.
Materials
Steel shoulder screws
These are our least expensive option.
They are produced to ISO 7379 standards.
Thread sizes from Ø4 M3 to Ø24 M20.
We manufacture special shoulder screws to customer drawings with a minimum batch size.
Stainless steel shoulder screws
We have three different grades of stainless steel shoulder screws:
A2 series – these are our are standard grade of stainless. They are strong and resistant to corrosion but not to very harsh environments such as salt water.
For standard sizes Ø6 M5 up to Ø16 M12, see our part no P0137. For miniature sizes down to Ø4 M3 see parts numbers P0130 and P0132.
416 series – these are made from harder stainless steel with improved shear strengths but the parts are more prone to corrosion (see part no. P0131 and P0133).
A4 series – these shoulder screws (P0143) are very resistant to corrosion but are considerably more expensive than other stainless versions.
A2 Stainless
416 Stainless
A4 Stainless
Shoulder bolts
Our range of precision shoulder bolts with hexagonal heads come in both steel (grades 8.8 and 10.9) and stainless steel (grade A2). These bolts are manufactured to DIN 609 and DIN 610. We also have shoulder bolts for construction, manufactured to DIN 7968.
DIN 609 standard length thread | DIN 610 short length thread | DIN 7968 construction | |
Grade 8.8 steel | P0138.SC | P0140.SC | P0142 |
| Grade 10.9 steel | P0139 | P0141 | |
| A2 stainless steel | P0138.A2 | P0140.A2 |
Product Selection Chart
| Part No. | Product image | Material | Head | Corrosion resistance | Strength | Ø/thread | DIN/ISO |
| P0130 |  | Stainless 303 (A2) Stainless 316 (A4) Titanium (gr. 2 & 5) | Hex socket | ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ ✔ | ✔ ✔ ✔ | Min: Ø4/M3 Max: Ø12/M10 | ISO 7379 |
| P0131 | | Stainless 416 | Hex socket | ✔ | ✔ ✔ | Min: Ø4/M3 Max: Ø12/M10 | |
| P0132 | | Stainless 303 (A2) | Slotted | ✔ ✔ | ✔ | Min: Ø4/M3 Max: Ø12/M10 | |
| P0133 | | Stainless 416 | Slotted | ✔ | ✔ ✔ | Min: Ø4/M3 Max: Ø12/M10 | |
| P0134 |  | Stainless 303 (A2) Stainless 316 (A4) | Hex socket | ✔ ✔ ✔ ✔ ✔ | ✔ ✔ | Min: Ø4/M3 Max: Ø8/M6 | |
| P0135 |  | Stainless 303 (A2) | Hex head | ✔ ✔ | ✔ | Min: Ø4/M3 Max: Ø12/M10 | |
| P0136 | | Steel 12,9 | Hex socket | ❌ | ✔ ✔ | Min: Ø4/M3 Max: Ø24/M20 | ISO 7379 |
| P0137 | | Stainless 303 (A2) | Hex socket | ✔ ✔ | ✔ | Min: Ø6/M5 Max: Ø20/M16 | ISO 7379 |
| P0138 | | Steel 8,8 Stainless 303 (A2) | Hex head (long thread) | ❌ ✔ ✔ | ✔ ✔ | Min: Ø9/M8 Max: Ø44/M42 | DIN 610 |
| P0139 | | Steel 10,9 | Hex head (long thread) | ❌ | ✔ ✔ | Min: Ø9/M8 Max: Ø38/M36 | DIN 610 |
| P0140 | | Steel 8,8 Stainless 303 (A2) | Hex socket (short thread) | ❌ ✔ ✔ | ✔ ✔ ✔ | Min: Ø9/M8 Max: Ø44/M42 | DIN 609 |
| P0141 | | Steel 10,9 | Hex socket (short thread) | ❌ | ✔ ✔ | Min: Ø9/M8 Max: Ø38/M36 | DIN 609 |
| P0142 | | Steel 8,8 | Hex head | ❌ | ✔ ✔ | Min: Ø12/M12 Max: Ø27/M27 | DIN 7968 |
| P0144 |  | Stainless 303 (A2) Zinc-plated steel | Pan head | ✔ ✔ ✔ | ✔ ✔ ✔ ✔ | Min: Ø4/M3 Max: Ø10/M8 | DIN 923 |
