What Is Cold Heading? How Cold-Forged Fasteners Are Made

Cold heading is a metal forming process that shapes wire or rod into fasteners and precision parts at room temperature, using hardened punches and dies to strike the material into a die cavity instead of cutting it away. Because the metal is displaced rather than removed, a cold-headed part keeps continuous grain flow, work-hardens as it forms, and generates almost no scrap.

If you buy rivets, screws, pins, or custom metal components in volume, cold heading is probably how most of them were made — and understanding it changes how you write an RFQ. It explains why a 5,000-piece order and a 500,000-piece order carry completely different unit prices, why a supplier pushes back on a sharp internal corner in your drawing, and why a cold-formed screw can outlast a machined one in a vibrating assembly. This guide covers the definition, the terminology confusion around cold forming and cold forging, the full production sequence from wire coil to plated part, the limits of the process, and what a cold heading supplier needs from you to quote accurately.

What Is Cold Heading? A Working Definition

Cold heading is a cold forging operation performed below the metal’s recrystallization temperature, normally at ambient shop temperature. A length of wire is fed into a machine, sheared into a slug of controlled volume, and then hit by one or more punches that force it to flow into the shape of the surrounding die.

The name comes from the original purpose: forming the head of a fastener. Hold a piece of wire in a die so only a short length protrudes, strike the exposed end, and the material mushrooms outward into a head. That single operation — called upsetting — is still the core of the process, though a modern header does far more than upset.

Three characteristics define it and separate it from every other way of making a fastener:

• No heat is added. The metal is formed cold, so there is no scale, no thermal distortion, and no furnace energy cost.
• No material is removed. Volume in equals volume out. A machined screw can leave 60–70% of the bar stock on the floor as chips; a cold-headed screw wastes only the shear burr and the trimmed slug on hex heads.
• The grain flows instead of breaking. Machining cuts through the wire’s grain structure. Cold heading bends and compresses it around the part’s contours, which is why cold-formed heads resist fatigue and shear failure better than machined heads of the same material and grade.

Speed is the commercial argument. Multi-station cold headers commonly run in the hundreds of parts per minute, with high-speed machines reaching around 400 parts per minute on simple geometries. That throughput is what makes a fastener cost cents rather than dollars.

Cold Heading vs. Cold Forming vs. Cold Forging: Sorting Out the Terms

These three terms get used interchangeably in the fastener trade, and technically they are not the same thing. The distinction matters when you compare quotes from different suppliers.

In practice, when a fastener factory says “cold forming,” it usually means the same production line you would call cold heading. The useful takeaway is directional: cold heading is a type of cold forging, and every cold-headed part is a cold-formed part, but not every cold-formed part was headed. A cold-extruded hollow pin with no upset head is cold forged and cold formed, yet nobody in the shop would call it a headed part.

One more distinction worth holding: hot forging heats the billet to red heat, which lowers the force required and allows dramatic shape change, at the cost of scale, looser tolerances, and higher energy use. Cold heading trades geometric freedom for precision, surface finish, and unit cost.

How Cold-Forged Fasteners Are Made: The Production Sequence

A finished cold-headed fastener passes through six phases. Only phase three happens inside the header itself; the rest is what separates a competent supplier from a cheap one.

1. Wire preparation

Everything downstream depends on the wire. Coils arrive as hot-rolled rod and go through a sequence built to make the material as formable as possible:

• Spheroidize annealing for medium and high-carbon steels, which converts hard lamellar pearlite into rounded carbides so the metal can flow without cracking under the punch.
• Descaling by pickling or mechanical shot blast, because any oxide scale carried into the die will score the tooling and mark the part.
• Lubricant coating, typically a zinc phosphate layer plus a soap or polymer film. This is the least visible step and one of the most consequential: an inadequate lubricant film means galling, short die life, and surface tears on the head.
• Wire drawing through carbide dies to the exact diameter the part’s volume calculation requires. Slug volume is fixed by wire diameter and cut length, so drawing tolerance directly controls head fill.

2. Feeding and cut-off

The wire feeds into the machine, and a cut-off quill and knife shear a slug of precise length. The shear is a controlled break rather than a clean cut, and the quality of that break shows up later as head concentricity and squareness. A supplier with worn cut-off tooling produces slugs with angled ends, which then upset off-center.

3. Forming in the header

The slug is transferred through a series of die stations, and at each station a punch strikes it once. This progression is where the geometry appears:

• Upsetting enlarges one end into a cone, then into the finished head profile — pan, flange, hex, countersunk, button, truss.
• Forward extrusion pushes material through a smaller die opening to reduce and lengthen the shank, useful for shoulder and step diameters.
• Backward extrusion forces material to flow up around the punch, in the opposite direction of punch travel. This creates hollow bodies, recesses, socket drives, and the cavity in a semi-tubular rivet.
• Trimming shaves the upset round head into a hex or square by pushing it through a shaped trim die. Hex bolts are almost always trimmed rather than formed directly, which is why hex heads produce a scrap ring while pan heads produce none.
• Piercing and coining punch through a web to open a hole, or impress a marking, grade symbol, or drive recess.

Simple parts finish in one or two blows. Complex parts run a progression of four, five, or six stations, each blow moving the material a controlled amount closer to the final shape. Trying to achieve too much deformation in a single blow is what causes head cracks and shoulder droop, so the progression design is the real engineering in cold heading.

4. Threading, usually by rolling

Threads on a cold-headed fastener are almost always rolled, not cut. The blank passes between hardened dies carrying the reverse thread profile, which press the crests and roots into the shank. Rolling is faster than cutting, produces no chips, and leaves the thread’s grain flow intact and its surface cold-worked, so a rolled thread has meaningfully better fatigue and stripping resistance than a cut thread of the same size. Because rolling displaces material outward, the blank diameter is deliberately made smaller than the finished thread’s major diameter.

5. Heat treatment

Cold working raises strength but consumes ductility. Depending on the grade and the specified property class, parts may then be quenched and tempered to reach a strength class, case hardened or carburized for surface wear resistance while keeping a tough core, or stress relieved and baked after plating to reduce hydrogen embrittlement risk in high-strength steels. Low-carbon rivets and many brass or aluminum parts skip heat treatment entirely, since the work hardening from forming is sufficient.

6. Finishing and inspection

Surface treatment is chosen for the service environment: zinc plating, zinc-nickel, black oxide, phosphate, nickel or tin plating on copper alloys, passivation on stainless. Inspection then covers dimensions against the drawing, head fill and crack checks, thread gauging with go/no-go rings, hardness and tensile verification where a property class applies, and — for critical assemblies — automated optical sorting to pull mixed or malformed pieces before packing.

Which Materials Cold Head Well

Formability, not strength, decides whether a material can be cold headed. The metal has to accept large plastic strain at room temperature without cracking, which means adequate ductility and a controlled inclusion content.

• Low and medium carbon steel — the workhorse. Excellent formability, low cost, and it responds well to heat treatment for higher property classes.
• Alloy steel — used where a high strength class is required after quench and temper; needs careful annealing and lubrication because forming loads are higher.
• Stainless steel — austenitic grades in the 300 series are standard for corrosion resistance. The specialist cold heading grades have lower carbon and adjusted nickel to reduce work hardening rate; free-machining grades with high sulphur are the wrong choice, because they crack under the punch.
• Aluminum and aluminum alloys — very formable and light, common in rivets and electrical hardware.
• Copper and brass — chosen for conductivity and corrosion resistance, particularly in electrical contacts and terminals.

Materials that resist cold heading are the brittle and the very hard: cast irons, high-silicon or leaded free-cutting alloys, hardened tool steels, and anything with a low elongation figure. If your part must be made from one of those, machining or hot forging is the honest answer.

Cold Heading vs. CNC Machining: How to Choose

Both processes make the same parts. They fail at opposite ends of the volume curve.

The practical rule: prototype and validate with machining, then move to cold heading once the design is frozen and the annual volume justifies the tooling. Suppliers that run both processes, as many fastener factories do, can quote the crossover point for your specific part rather than pushing you toward whichever line they happen to own.

Where Cold Heading Stops Making Sense

An honest look at the limits will save you a wasted RFQ cycle.

Tooling economics. Every part geometry needs its own die and punch set. On a 3,000-piece order the tooling can dominate the price; on a 300,000-piece order it disappears into the unit cost. Low-volume buyers often get a better total price from machining even though the per-part forming cost is higher.

Geometry limits. Material flows where pressure sends it, which rules out undercuts, re-entrant features, cross-drilled holes, and sharp internal corners in the formed operation. Extreme upset ratios — a very large head on a very thin shank — risk cracking, and very long thin shanks risk buckling under the punch. Radii your drawing calls out as sharp will come back from the supplier as a request for a fillet.

Size range. Cold heading is most economical on small to mid-size fasteners. Very large diameters demand forming pressures that push you toward hot or warm forging.

Secondary operations. Anything the header cannot form has to be added afterward: cross-holes, slots, keyways, knurls, grinding to a tight concentricity spec, or a tapped internal thread. Those operations are normal and often unavoidable, but each one adds cost and a handling step, so a design that eliminates two of them is materially cheaper. This is where CNC and punch press capability alongside the headers earns its value, because the part never has to leave the factory to be finished.

What Cold-Headed Parts Look Like in the Field

Cold heading produces far more than bolts. Typical output includes solid, semi-tubular, and tubular rivets; machine screws, self-tapping screws, and shoulder screws; nuts and weld nuts; dowel pins, clevis pins, shoulder pins, and stepped pins; contact rivets and terminals for electrical hardware; ball studs, sockets, and small shafts for automotive assemblies; door lock and latch components; and hollow or stepped custom parts for appliances, furniture hardware, and electronics enclosures.

By industry, the pattern is consistent: automotive for pins, studs, and fasteners that must survive vibration and fatigue cycling; electrical and electronics for contact rivets, terminals, and enclosure hardware where conductivity and consistency matter; appliance and furniture hardware for high-volume, cost-sensitive fasteners; construction and industrial equipment for structural and assembly fasteners; and medical and aerospace where continuous grain flow supports the fatigue requirement.

How to Spec a Cold-Headed Part in Your RFQ

Most quoting delays come from missing information, not from difficult parts. Send these seven items and a cold heading supplier can price your part in one pass instead of three:

1. A dimensioned drawing with tolerances, including which features are critical and which are reference. A photo or sample helps, but tolerances cannot be inferred from either.
2. Material grade and standard — DIN, ISO, ASTM, JIS, or GB, with the grade or property class. “Stainless” alone is not specifiable; 304, 305, and 316 head differently and cost differently.
3. Annual volume and order size, plus whether you want scheduled releases. This is the single biggest driver of unit price, because it sets how tooling is amortized.
4. Surface finish and thickness, with the corrosion requirement behind it, such as a salt spray hour target.
5. Heat treatment or mechanical property requirements — hardness range, tensile class, core and case specification.
6. The application and load direction. Shear, tension, vibration, service temperature. A supplier who knows the load can suggest a cheaper geometry that still passes.
7. Packaging, marking, and documentation — bulk, bagged, tray, or tape; PPAP, material certificates, RoHS or REACH declarations, dimensional reports.

If any of these are still open, say so rather than guessing. A supplier quoting against an assumed grade will re-quote once the real grade appears, and you will have lost a week.

Frequently Asked Questions

What is cold heading in manufacturing? Cold heading is a cold forging process that forms wire or rod into fasteners and precision parts at room temperature. Punches and dies strike a cut slug of metal, forcing it to flow into the die cavity to create a head, flange, shank, or hollow feature. No heat is applied and no material is machined away.

Is cold heading the same as cold forming or cold forging? Not exactly. Cold forging and cold forming are broad terms for any room-temperature plastic deformation of metal. Cold heading is the specific subset that forms a head or upset on one end of a slug. In everyday fastener-industry conversation the three are used interchangeably, and for most purchasing decisions that is harmless.

Why are cold-headed fasteners stronger than machined ones? Two reasons. Cold heading preserves continuous grain flow, bending the material’s grain around the part’s contours instead of cutting through it, which removes the stress concentrations a machined head-to-shank transition creates. Second, plastic deformation work-hardens the metal, raising yield strength without any change of grade.

Are threads on cold-headed fasteners rolled or cut? Rolled, in nearly all production. Thread rolling presses the profile into the blank between hardened dies, producing no chips and leaving the thread surface cold-worked and its grain unbroken. Rolled threads outperform cut threads in fatigue and thread-stripping resistance at the same size and grade.

What tolerances can cold heading hold? Formed features commonly hold to about ±0.002 in (±0.05 mm) directly out of the header, with no secondary operation. Tighter tolerances, or tolerances on features in more than one plane, generally require a secondary machining or grinding step, which is why a drawing’s critical dimensions should be marked as such.

What is the minimum volume that justifies cold heading? It depends on how complex the tooling is and how long the part will stay in production, but the crossover against machining typically falls somewhere in the tens of thousands of pieces per year. Below that, machining often wins on total cost; above it, cold heading pulls away quickly. Send your annual volume and a supplier can calculate the crossover for your specific part.

Which materials cannot be cold headed? Anything too brittle or too hard to flow at room temperature: cast iron, hardened tool steel, free-machining alloys with high sulphur or lead content, and alloys with low elongation. Those parts belong on a machining or hot forging route.

Do cold-headed parts still need heat treatment? Only when the specification calls for it. Low-carbon rivets, brass contacts, and aluminum parts usually ship as formed, since cold working alone gives adequate strength. Fasteners with a property class, or parts needing surface wear resistance, go through quench and temper or case hardening, and high-strength plated parts are baked to mitigate hydrogen embrittlement.

Source Cold-Headed Fasteners and Custom Parts from yiwan.net

Understanding cold heading is useful; finding a factory that runs it consistently is what actually ships your product. Yueqing Yiwan Hardware Co., Ltd. is a manufacturer in Yueqing, Wenzhou, Zhejiang Province, China, built around multi-station cold upsetting alongside CNC turning, Taiwan and Ningbo automatic lathes, instrument lathes, and punch press capability — which means a part can be headed, machined, and finished under one roof instead of being shuttled between subcontractors.

We produce rivets including stainless steel semi-tubular rivets, screws, nuts, pins, cold forged parts, and CNC parts, in steel, stainless steel, aluminum, brass, and copper, to DIN, ISO, ASTM, and customer drawings. Our work concentrates on custom OEM components: automotive parts, door lock parts, and electrical hardware, exported to customers worldwide.

Send your drawing, material grade, and annual volume, and we will come back with a manufacturability review and a quote — including whether cold heading or machining gives you the lower total cost at your volume. Request a quote from yiwan.net and get an engineering answer on your part, not just a price.

Related reading: Rivets vs Screws vs Bolts: Which Fastener Should You Use?