Capability

Thread Rolling

Threads formed by pressure, not cut by removal

Grain-flow threadNo chipsSmoother flankHigher fatigue life

Thread Rolling · Bekasi plant

Process overview

Threads formed by pressure, not cut by removal

A cut thread is a series of small cuts through the material, and every cut leaves a notch at the root. A rolled thread is formed by pressing the blank between dies, so the material is displaced rather than removed — the grain runs along the thread profile instead of being severed across it.

The practical consequences are a stronger thread, a smoother flank, no chip waste and a more consistent pitch. For a micro screw this matters more than for a large bolt, because the thread is a much larger fraction of the part: at M1.0 there is very little material at the root, so anything that improves the root condition has a disproportionate effect on how the screw performs.

Step by step

How the process runs

Each step has a defined control point. The sequence is not arbitrary — changing it changes the result.

Blank preparation

The formed blank is brought to the diameter the rolling dies are set for, so that the thread is displaced to the correct major diameter.

Die set-up

Flat or cylindrical dies are set to the pitch and flank angle of the thread specification.

Rolling

The blank is rolled between the dies and the material flows into the thread form, with the grain following the flank.

Gauging

Threads are checked with GO / NO-GO ring gauges and the major diameter is measured against the drawing.

Post-rolling route

Parts go to heat treatment or coating as specified, with thread gauging repeated after coating where the finish affects the fit.

Specification

Process window and capability

The numbers below define what the process can hold repeatably. They are not laboratory bests.

Process

Thread rolling — material displaced, not cut

Grain structure

Continuous along the thread flank; no severed grain at the root

Surface

Smoother flank than a cut thread

Waste

No chip production

Thread forms

Machine thread coarse and fine pitch; self-tapping forms

Verification

GO / NO-GO ring gauge and major diameter measurement

Re-gauging

Repeated after coating where the finish affects the fit

Equipment

What the line is built on

Capacity figures are per machine and assume a standard part. Complex geometry reduces throughput.

Equipment	Specification
Flat die thread rolling	Thread forming between reciprocating flat dies
Cylindrical die rolling	Thread forming between rotating cylindrical dies
Thread ring gauges	GO / NO-GO verification per lot

Process control

What is checked, and when

A control that is not recorded is not a control. Each item below generates a record linked to the lot code, retained for the programme duration.

Quality & certifications

Blank diameter checked before rolling

Die condition and set-up verified at start of run

GO / NO-GO ring gauge per lot

Major diameter and pitch measurement

Thread length and runout against drawing

Re-gauge after plating or coating

Questions

Thread Rolling FAQ

Practical questions from sourcing and engineering teams.

Considering a process change? If a tolerance or finish is not achievable on our current line, we will say so before quoting rather than after the first lot.

Is a rolled thread always better than a cut thread?

For a screw that sees fatigue or repeated load, yes — the continuous grain and the compressive stress at the root both improve behaviour. Cutting is only relevant where the profile cannot be rolled, such as very short runs of a non-standard form where a die is not economic.

Does rolling change the thread dimensions?

It changes how the material sits, because the thread is displaced from the blank rather than cut into it. That is why the blank diameter is controlled before rolling — it determines the finished major diameter.

Why re-gauge after coating?

Because a coating adds thickness to the flank. A plated thread can move from a passing to a failing gauge, and for a close fit that matters. Gauging after coating is the only way to know what the customer will actually receive.

Can self-tapping threads be rolled?

Yes. Self-tapping and thread-forming forms are rolled in the same way, and the process is what gives them the clean flank that lets them form a thread in plastic without tearing it.

Related capabilities

What happens before and after

These processes are usually sequenced with the one above.

Capability

Cold Forging

Single- and multi-station cold heading forms the screw from wire, so the grain follows the part contour and no material is machined away.

Precision screw family produced from in-house heading dies

Capability

Tooling & Die Shop

Heading dies and punches are designed and built in-house, so geometry can be changed during development instead of waiting for an outside toolmaker.

Heat treated black oxide socket head screws

Capability

Heat Treatment

Hardening, tempering and case hardening set the balance between a wear-resistant surface and a core that will not fracture — with hydrogen relief where plating demands it.

Need thread rolling for your part?

Send the drawing and the annual volume. We will confirm feasibility, tolerance and lead time in the quotation.

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