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Direct supplies tooling for metal processing from Taiwan


Cylindrical Dies are ideal for a wide range of precision threaded parts. They are made for through-feed rolling and In-feed rolling.

It has for 2- and 3-Die Systems, so cylindrical Die mechanism can be classified as “Two rollers Die” and ”Three rollers Die”, meaning two or three areas of insertion.

Threads are imprinted with two moving cylindrical Dies, or when parts between either two or three spinning. Cylindrical Die is much slower than flat Die but maintain far better run-out and excellent thread quality.


Highest quality both dimensionally and metallurgically.

Multiple possibilities and advantages


Used with thread rolling machine and automatic lathes for small diameter

For making possible the threading of very hard materials or large-size trapezoidal profiles with greater precision and quality.

Thread rolling cylindrical Dies

Specification of thread rolling cylindrical dies

thread rolling cylindrical dies
D : Outer diameter, T : Width, d : bore diameter, F : key-way width, H : key-way depth

Production capability range

  • Outer diameter - MAX. 400mm
  • Width - MAX. 300mm
  • Bore diameter - MAX. 100mm
  • Pitch diameter - MIN. 0.4mm

How to order Thread rolling cylindrical Dies

1 Model Name of manufacturer or model
2 Spindle inclination In feed or Through feed
3 Approx. Outer diameter Specify of outer diameter is required.
4 Width Usually set up by entrance length, parallel length, chamfer length, mostly select width of 40, 50, 60, 70, 80 mm.
5 Workpiece
  1. Dimensions
  2. Outer diameter
  3. Pitch diameter
  4. Roots diameter
  5. Crest angle
  6. Class limit
  7. Thread length
6 Others Other special conditions (such as reversal lead )

Normally there are 2 or 3-piece rolling dies in a set with higher precision but lower production speed, generally used in irregular-shape workpiece.

Planetary Dies

Planetary dies
Combination of a segment die and a rotary die, with highest production rate than other thread rolling dies, generally used for mass production.

How to order planetary Dies

  1. Machine model
  2. Width of Dies
  3. Thread size
  4. Workpiece and hardness
  5. Other special requirment

Production capability range

Segment Die (RSD)
Outer diameter : Max. 600mm
Width : Max. 165mm
Pitch : Max. 0.4mm (64thread/ inch)

Rotary Die (RCD)
Outer diameter: Max. 470mm
Width : Max. 300mm
Pitch : Max. 0.4mm (64thread/ inch)

Radius run- out

By rounding the sharp crest of incompleted threads on die edges which can increase dies durability. Radius Run-out is mainly used for dies in the bolt production industry, such as high tensile screws, aircraft screw, automobile screw as well as any special-purpose machinery, particularly where high durability is required.

The breakage position of bolt

Material / Breakage position Under head Shank Incomplete thread Effective thread Nut engagement Internal part
SCM24 78 22
SCM23 6 59 17 12 6
Low carbon steel : Cr serious 39 33 19 3 3
Low carbon steel: Cr- MoCr serious 100
Boron steel 39 36 25

Types of radius Run-out

Type S C I
Symbol RR-S (R-S) RR-C (R-C) RR-I (R-I)
Top and bottom (Top only ) Top and bottom (Top only ) Top and bottom (Top only )
Radius size of crest Rn ≥ Crest radius of complete thread Rn ≥ 0.108 Pitch Rn ≥ 0.072 Pitch
Standard Imperfect thread will have larger radius than regular threads. Imperfect thread will have 0.0108 Pø over radius. Imperfect thread will have 0.072 Pø over radius.

General options of Radius Run-out angles.

Avalible range of Radius Run-out : Rolling dies, flat dies, and planetary dies with pitch diameter over 0.4mm.

Comparison of incomplete thread with and without Radius Run-out