Flange Bolts & Serrated Screws
Flange bolts with serrated bearing faces, spread the load and bite into the joint.
Flange bolts for joints where the hole is larger than the bolt or the surface is painted. The serrations on the underside bite through coating and share the clamp load over a wider area.
How we make it: Swiss CNC machining service →
3–5 weeks
1000 pieces
ISO 9001:2015 · IATF 16949
Technical Specifications
| Parameter | Value | Unit |
|---|---|---|
| Thread range | M5–M20 | metric |
| Flange diameter | ±0.3 | mm |
| Serrations | Standard or free-spinning | - |
| Property class | 8.8 / 10.9 | - |
| Under-head radius | Large | note |
| Coating | Zinc flake preferred | note |
Available Materials
- Steel 8.8 / 10.9
- Stainless A2 / A4
- Zinc flake coated steel
Typical Applications
- Automotive assembly
- Sheet metal structures
- Appliance assembly
- Structural framing
- Machinery panels
Surface Finishes
- Zinc flake (Dacromet)
- Zinc-nickel
- Black oxide
- Passivate
- Zinc plating
Industries Served
- Automotive & EV
- Appliance Manufacturing
- Industrial Equipment
- Rail
- Building Services
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 M5–M20 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.
- Order size
- Minimum order is 1000 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.
- Certification and paperwork
- ISO 9001:2015, IATF 16949. On a certified family the inspection and documentation work is part of the price: first article inspection, material traceability and the dimensional report are produced per order, not per sample.
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
- First article inspection to AS9102, because this family carries an aerospace or automotive certificate
The full equipment list, with counts, is on the capability page; the inspection sequence is on quality and inspection.
Questions buyers ask
- Do serrated flanges damage the coating?
- They cut into it, which is the intent - the serrations reach bare metal and give electrical continuity as well as friction. On a cosmetic painted face, use a plain flange instead.
Related part families
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Custom Bolts & Screws
M3–M48 bolts and screws to ASTM, ISO and DIN, thread rolled after heat treat so grain flows with the thread.