VNIIINSTRUMENT

• Unpolished solid rods, diameter 1.2 to 40.2 mm, L=310 / 330 mm
• h6 polished solid rods, diameter 1 to 40 mm, L=310 / 330 mm
• Unpolished rods with one hole, diameter 4.5 to 32.3 mm, L=310 / 330 mm
• Unpolished rods with two straight holes, diameter 4.2 to 34.4 mm, L=310 / 330 mm
• Unpolished rods with two helical twisted holes 30°, diameter 3.3 to 35.3 mm, L=310 / 330 mm
• Unpolished rods with two helical twisted holes 40°, diameter 6.3 to 32.3 mm, L=310 / 330 mm
• Unpolished rods with three helical twisted holes 30°, diameter 4.8 to 33.3 mm, L=310 / 330 mm
• Unpolished rods with three helical twisted holes 40°, diameter 6.3 до 32.3 mm, L=310 / 330 mm

 

Also produced:

• various shaped bars
• blank shapes for specific tools, based on customers’ drawings
• rods with special tapered holes and side holes

 

Both solid end-cutting tools and those with coolant holes are used in automotive and aerospace industries. The basic requirements for these tools are high cutting performance, hardness and high quality machined surfaces. Therefore, the carbide rod production process focuses on enhancing the quality of the raw material. Wear resistance depends on hardness but enhancing hardness might lessen the bending strength of the rod and its impact resistance. The grain structure and cobalt content determine the physical characteristics of the alloy – hardness, toughness and wear resistance.

Alloy	Cobalt content wt.%	HV30		KIC MNm-3/2	TRS N/мм2	WC-O мкм	Applications
		HV30 кг/мм2	HRA ISO 3738
K20F	8,0	1710 ± 40	92,8	0,0	3200	0,7	Grey cast iron, hardened steel, age hardening aluminium alloys, plastic with fillers, fiberglass reinforced plastics.
K6UF	6,0	1900	93,8	9,3	>4000	0,6	Boring of composite materials, bores for circuit plates 0 0,1 mm to 0 0,5 mm.
K40UF	10,0	1610 ± 40	92,3	10,5	>4000	0,6	Titanium alloys, heat-resistant alloys, austenitic stainless steels, grey cast iron, fiberglass reinforced plastics.
K44UF	12,0	1680	92,5	10,0	>4000	0,5	Drilling/Milling applications, e.g. for titanium alloys, heat-resistant alloys, stainless steels, hardened steels, grey cast iron, fiberglass reinforced plastics, composite materials. For machine taps.
K55SF	9,0	1920	93,9	9,3	>4000	0,2-0,5	Drilling/Milling applications, e.g. for high wear resistance materials, for stainless steels, for composite materials like Kevlar and GRP. For high speed cutting, for dry cutting.

Table 1.

Physical characteristics of alloys K6UF, K40UF , K44UF and K55SF

In K40UF, the cobalt content is 10% and the grain size is 0.6 microns. In K44UF, a fine grain structure of 0.5 microns is used with a high cobalt content of 12%. The toughness for both the alloys is almost the same, but the hardness of K44UF is 5% higher than that of K40UF. For manufacture of K55SF, 0.2 microns grain is used and the cobalt content should not exceed 9%. This enhances the hardness by 24% (1920 kg/microns) and reduces toughness by 5%.

Konrad Friedrichs GmbH & Co.KG Firm

Carbide production in Kulmbach, Germany, started in 1988. Since then, besides rods and bars, hand-moulded and other special shapes were manufactured. A significant achievement, which also gave direction to the whole production, was the designing of rods with straight and twisted coolant holes. Manufacturers of high-quality tools show an ever-growing demand for these products.
The production process for various sizes of rods with different kinds of holes is being continuously optimized and technologies improved. The world-wide patented production process for rods with helical twisted holes, top quality of products, know-how and custom-tailored approach allows Konrad Friedrichs GmbH & Co.KG to play a major role in the international market of carbide rod manufacturers.
Carbide alloys K44UF, K55SF and K6UF are the top three on the list of carbides in the world. The firm manages to meet and exceed the ever-growing demand of the tools market. It focuses on constant improvement of existing alloys especially in terms of material characteristics like hardness and toughness to customers’ needs. No less important are other characteristics like efficiency and high speed of cutting, hard cutting and application to new composite materials and are also improved continuously. In 2005, the firm increased the scope of research in these areas and allocated more resources to these projects.
The whole team of Konrad Friedrichs GmbH & Co.KG is ready to enhance their flexibility and know-how to give the optimum customer service.

KF high-tech carbide materials

The firm has developed its own standard and high-tech alloys for different cutting operations like boring, milling, shaping etc for different materials - grey cast iron, hardened steel, aluminium alloys, titanium alloys etc. Sintered carbide with ultra fine grain structure is the basis for carbide materials with enhanced hardness without reduction of toughness or cutting characteristics. Thus the customer gets just what is needed – special carbide alloys with enhanced wear resistance and impressive toughness characteristics. The table gives characteristics of carbide alloys.
Fine grain carbide alloy K20F (grain size 0.7 microns) is good for solid carbide point tools. It can be widely used instead of K series alloys. It can also be used as a standard alloy for cutting grey cast iron, hardened steels, age hardening aluminium alloys, plastic with fillers, fiberglass reinforced plastic, break shoe lining etc.
The universal carbide material K40UF has the widest application range. K20Fis composed of ultra fine grain tungsten carbide of 0.6 mm and has a relatively high cobalt content (10%). This results in high hardness coupled with high toughness and bending strength. The alloy which is very good for boring and milling works, has also become a standard for high quality boring due to its long life characteristics and durable cutting edge. It is used for cutting hardened alloys, stainless steels, titanium alloys and fiberglass reinforced plastic.
K44UF carbide material is based on a very uniform ultra-fine tungsten carbide grain structure of 0.5 microns with 12% cobalt which allows high bending strength and toughness without any compromise on hardness. It is used for boring and for machine taps. It also shows outstanding results in milling titanium alloys, age hardening alloys, grey cast iron, stainless and hardened steels, fiberglass reinforced plastics and other composite materials.

K40UF material with grain structure of  0,65 microns (zoom х 5000)	K44UF material with grain structure of  0,5 microns (zoom х 5000)	KS5UF material with grain structure of  0,2 - 0,4 microns

The firm’s latest design, carbide K55SF for finest operations has set a new quality level. The important quality of hardness of this carbide depends upon the use of superfine grain tungsten carbide powder of 0.2 to 0.4 microns. This alloy ensures perfect durability of the cutting edge, highest resistance to wear and extreme toughness. The range of application is very wide – from wear-resistant materials like stainless steels, hardened steels, graphite composite materials and age hardening aliminuim alloys to difficult composite materials like Kevlar and GFRR. The outstanding characteristics of this carbide material allows its use in highest-speed cutting.
Another new design - K6UF carbide material - was elaborated especially for deep boring and deployment operations. This alloy is characterized by high hardness and wear-resistance and has 6% cobalt content.

Research, achievements and quality

The production has a DIN EN ISO 9001:2000 certificate, which confirms the constant high quality of carbide alloys with a grain structure of under 1 micron. In the course of production every paper and document is stored, which allows to get back to an earlier manufactured product and resume its production. Highly qualified scientists work with experienced specialists as a team which ensures successful cooperation, benefits overall production and results in improved know-how for high-tech carbide materials applications.

A competent team manages the complicated production and the extensive quality control processes. The firm’s management board focuses on improvements of the production process for high-tech carbide materials with fine grain of under 1 micron. Special attention is paid to a holistic approach to new challenges because carbide alloys are always developed for a specific purpose and application.

High-tech carbide materials for cutting tools

Nowadays there are two trends in machine building and tooling industries. One demands higher hardness of cutting tools, increased cutting speeds and better performance. After high-speed steel tools were replaced by carbide tools for boring, milling and turning, the tooling industry focused on developing new kinds of alloys for high-speed operations in order to reduce costs for metal processing. The other dictates higher requirements for carbide tools in new areas of application and for new materials like composites – Kevlar and fiberglass reinforced plastic. Higher wear-resistance and improved physical and mechanical characteristics are crucial for the new alloys.

End-cutting tool rods

Both solid end-cutting tools and those with coolant holes are applied in automotive and aerospace industries. The basic requirements for these are high cutting performance, hardness and high quality of machined surface. In connection with the above, the carbide rod production process focuses on enhancing quality of the raw material. Wear resistance depends on hardness, but enhancing hardness might lessen the bending strength of the rod and its impact resistance. The grain structure and cobalt content determine the physical characteristics like hardness, toughness and wear resistance of the alloys.

The highly dispersed fine grain of sintered carbide ensures excellent micro-structure of the carbide alloy. The key factor however, is technology, which prevents grain growth during sintering and inclusion of special fillers in strict proportions which ensure specific physical and mechanical characteristics in the material. The latest materials meet all requirements for physical and mechanical characteristics.

The table shows data for K6UF, K40UF, K44UF andK55SF. In K40UF, cobalt content is 10% and the grain size is 0.6 microns. In K44UF, a grain of finer structure is used (0.5 microns) and has a high cobalt content of 12%. The toughness for both alloys is almost the same but the hardness of K44UF is 5% higher than that of K40UF. For the production of K55SF, 0.2 microns grain is used and the cobalt content cannot exceed 9%. This enhances hardness by 24% (1920 kg/ microns) and reduces toughness by 5%.

The firm manufactures about 40 tons of rods a month which suffices to meet the market demand for high-performance and wear-resistant carbide shapes used to make all kinds of tools. There are five sintering systems in the shop as shown in the picture. Permanent research works, outstanding experience and know-how ensure high quality of the products. Further, high flexibility, short-term delivery and presence in all external markets ensure good customer service and mutually beneficial cooperation between the distributors and the firm.