Flat Thread Rolling Dies

Flat Thread Rolling Dies

Flat Thread Rolling Dies2023-09-15T07:04:55+00:00
  • Flat Thread Rolling Dies
  • Single face Dies

Flat thread rolling dies, also called Flat milled dies or flat rolling dies, are tools used in the manufacturing process to create a rolled thread on cylindrical objects. The rolled thread provides greater tensile strength compared to cutting threads, as well as increased precision and durability.

We are a professional thread rolling dies manufacturers,these thread rolling flat dies are available in a variety of shapes and sizes depending on the type of thread being created and can be used to save costs and time in the production process.

The principle of Thread Rolling Flat Die is the oldest process of coldforming threads. This process uses a pusher blade to insert the work piece into coldforming area between both flat dies. Afterwards the thread is formed within one working stroke. Flat thread rolling die applicationsScrews of flat thread rolling dies

We are able to design tools and accessories according to the finished product drawings and technical requirements. It is necessary to specify the model of the machine, the material of the dies, the dimensions of the dies, the diameter of the wire, the dimensions of the product, the accuracy and pitch of the thread, the metric and inch specification of the thread, the shape of the outer surface of the dies (round, square, hexagonal, prismatic), the dimensions S, H, L1, L2, as well as the number of sets to be purchased.

In addition, other factors that need to be taken into account include thread depth, thread angle, thread root radius, and thread flank angle.

Single face Dies
Single face Dies

Duplex face Dies

Material Standard: All of our flat dies are made from high-quality imported steel such as DC53, SKH-9 that have been tested and approved in Japan, Germany, and Sweden. In addition, the steel undergoes pressurized cooling and vacuum heat treatment to ensure that the saw blade is wear-resistant and heat-resistant, with good toughness thereby ensuring its standard service life. In addition, we can provide nitriding treatment on the surface of the thread rolling flat dies, which can increase its service life by 50% compared with the non-nitrided type.

Material Hardness (HRC) Features Applications
SKD11 58-61 SKD11 tool steel has good wear resistance and size ability after heat treatment. Used for tensile dies, cold extrusion dies, first punch holder, etc.
DC53 (Daido) 61-63 DC53 steel is high toughness and high chromium steel, has wear resistance, stamping resistance, and high material resistance. It is often used in the manufacture of demanding molds, such as impact cold forging dies, deep drawing dies, molds, and flat dies for stainless steel screws, etc.
SKH-9 61-64 SKH-9 steel is general-purpose high-speed steel with high wear resistance and toughness. Used for cold forging dies, punches, flat dies, punch pins, etc.


  • High Precision: Flat thread rolling dies with precision classes 1, 2, or 3 can be manufactured and processed according to specific precision requirements.
  • High Wear-Resistance: Through a series of heat treatments, the hardness of the flat dies can reach HRC 63, resulting in stable performance and high efficiency.
  • Versatility: Flat thread rolling dies materials such as Cr12MoV, DC53, and high-speed tool steel can be offered, and thread forms such as ANSI, BS, DIN, and JIS are also available.
What is a flat die?2023-07-12T00:54:22+00:00

A flat die is a special cutting tool used for processing taps and bolts. It consists of two square templates on top of a threading machine, one long and one short, with teeth patterns used to mold the screw or bolt into threads.

Flat dies are the most commonly used thread tools in the standard fastener industry for processing screws and bolts. The processing principle mainly uses cold extrusion forming, which has the advantages of high production efficiency, low processing cost, high precision and strength of the produced threads, and good surface quality, and has been widely used.

Flat dies are generally formed by cold rolling and are not processed after heat treatment. During operation, the teeth must withstand severe impact loads and extrusion stresses. After heat treatment, the hardness of the teeth below 3 to 5mm from the tooth root is 58 to 61HRC, the martensite of quenching is less than grade 3, and there is no decarburization on the tooth surface.

What are the common problems and corresponding solutions for flat thread rolling dies with pointed tails?2023-07-12T00:38:50+00:00

Broken points:

  • Reduce the inclination angle.
  • Grind more material at the feeding end of the grinding machine and less at the output end, causing an increase in feeding and a change in the cutting form.

High stress on thread rolling dies, smoking, and hot screws:

  • Maximize the chamfering position for feeding.
  • Make the chamfer sharper, with a sharpness of 2-3mm for the short die.

Difficulty adjusting the machine:

  • The difference between the centerlines of the short and long dies must be traced back to the original centerline marking method.
  • The coordinates of the short and long dies must be consistent during chamfering, and CNC automatic control is preferred.

Dull thread bottoms and peeling:

  • The coordinates of the chamfer for the long and short dies must be consistent.
  • The anti-skid teeth generally only reach the centerline (they can be appropriately lengthened in the case of different thread lengths).
  • The anti-skid teeth must be pressed first and then chamfered or milled with a tool (must be implemented within three years).
  • The anti-skid teeth should not be too deep (specifically shown in pictures).

Peeling at the bottom of the pointed threads:

  • The milling teeth on the slope are too small or the chamfer on the slope is too large, both of which cause too much material on the slope (CNC programming has a better effect).
  • The outer diameter of the thread at the turning line is easily too large, and burrs easily accumulate at the bottom of the thread. In particular, the pointed tail of the machine screw is cut flat, the round tail, and the pointed tail of the machine screw has no teeth.

Blackening and heating at the tip, and easy wear on the slope:

  • Increasing the slope can improve the problem.
  • Push more material out while grinding the pointed tail, causing a complete change in the cutting method so that the tip is not under stress.
  • Open the chamfer on the slope for the 2nd to 4th teeth during feeding, and it is best to use CNC control.
What are the heat treatment processes for flat thread rolling dies?2023-07-11T08:08:03+00:00

The main heat treatment processes for flat thread rolling dies are tempering heat treatment and carburizing heat treatment.

  • Purpose: To achieve higher hardness and strength for screws after cold forming.
  • Function: Achieve self-locking attachment of metal, improve mechanical properties of metal components such as torsion resistance, tensile strength, and wear resistance.
  • Tempering Heat Treatment (does not add elements to the metal, changes the internal structure of the metal by temperature variation to obtain better mechanical properties): Products with a strength level of 8.8 or higher are all products of tempering heat treatment. The characteristic of this heat treatment is that the hardness is relatively uniform inside and outside.
  • When heat treating the same material, the higher the hardness, the worse the toughness. Therefore, there needs to be a safe match to ensure that toughness is guaranteed while meeting the hardness requirements.
  • Carburizing heat treatment: adding carbon elements to the metal component to increase its surface hardness, targeting metals with low carbon content. Self-tapping screws basically all require this treatment, which is characterized by a very hard surface and a relatively soft core because it needs to be screwed into a hard iron plate.


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