The blank is cut from coil and struck into a die. Because nothing is removed, the grain flow follows the shape of the part instead of being cut through it — which is why a cold-headed head is stronger at the head-to-shank fillet than a machined one of the same material, and why almost every high-volume bolt and screw in the world is made this way. The work hardening that comes with it raises the tensile strength of the finished blank before any heat treatment.
What Cold Heading is the right choice for
- High volumes — the cycle is measured in parts per second, not parts per minute
- Parts where head-to-shank strength matters
- Standard and near-standard fastener shapes
- Minimising material cost: there is no swarf
Where it is the wrong choice
- Tooling has to be made, so it is the wrong process for a few hundred pieces
- Deep undercuts and sharp internal corners are difficult to form
- Very long parts relative to diameter need a secondary operation
Parts produced this way
- Custom Bolt — 75 standard parts in the catalog
- Custom Screw — 114 standard parts in the catalog
- Custom Nut — 100 standard parts in the catalog
- Custom Rivet — 24 standard parts in the catalog
- Custom Pin — 34 standard parts in the catalog
Usually combined with
Cold Heading is rarely the only operation on a part. On most jobs it sits in a sequence with:
Order terms
- Minimum order
- 2,000–5,000 pieces. The exact figure depends on the part: it is set by the tooling the drawing calls for, and is confirmed when the drawing has been reviewed.
- Samples
- Within 7 days of drawing approval.
- Drawing
- Preferred, but not required — a sample, photographs or a sketch is enough to start.
What a quotation needs
Nine things, and a drawing settles most of them at once. Where a field is unknown, say so — an assumption stated is better than a blank, and several of these can be recommended rather than specified.
- Drawing
- A 2D drawing (PDF or DWG) or a 3D model settles almost every other question on this list at once.
- Dimensions
- Diameter, length, head size and any features — enough to know what is being made.
- Tolerance
- Tolerance is the single biggest cost driver. Tell us which dimensions are critical and which are not — holding everything tight costs money on features nobody measures.
- Material
- Carbon steel, alloy steel, stainless, brass, aluminium, titanium — or the application, and we will suggest one.
- Strength grade
- Property class to ISO 898-1 (8.8, 10.9, 12.9) or stainless class to ISO 3506 (A2-70, A4-80). This decides the material and the heat treatment together.
- Thread standard
- Metric coarse, metric fine, UNC, UNF, BSW or a pipe thread — and the tolerance class if it is specified.
- Surface finish
- Zinc, hot-dip galvanised, black oxide, Dacromet, Geomet, nickel, passivation, or plain. Salt-spray hours if you have a requirement.
- Quantity
- Annual volume and first-order quantity. Volume changes which process is the right one, so it changes the price more than most buyers expect.
- Application & environment
- What the part holds together, and what it has to survive — temperature, vibration, chemicals, salt. This is what lets us catch a specification that will not work before it is made.
Questions
What is the minimum order quantity for a custom part?
Between 2,000 and 5,000 pieces for most parts. The exact figure depends on the part: it is set by the tooling the drawing calls for, and is confirmed when the drawing has been reviewed.
How long does a sample take?
Within 7 days once the drawing has been approved. The drawing stage comes first, and for a part being reverse-engineered from a sample it is where most of the time goes.
Can you make a part without a drawing?
Yes. A physical sample, photographs against a scale, or a dimensioned sketch are all workable starting points. A drawing is produced from whichever of those you have and sent back for approval before anything is made.
When is Cold Heading not the right process?
Tooling has to be made, so it is the wrong process for a few hundred pieces. Deep undercuts and sharp internal corners are difficult to form. Very long parts relative to diameter need a secondary operation.
Which fasteners are made by cold heading?
In this catalog: bolt, screw, nut, rivet, pin. Whether it is the right process for a particular part depends on the drawing and the quantity.
Send the part
A drawing answers most of this at once. If you do not have one, fill in what you know and attach a photograph — samples follow within 7 days of the drawing being approved.