PCD Tipped Carbide Boring Bars

PCD Tipped Carbide Boring Bars

PCD Tipped Brazed Boring Tool. For Bore sizes smaller than 8 mm in diameter. PCD is brazed directly to a tungsten carbide shank providing a rigid boring tool capable of remarkable surface finishies and providing a high productive alternative to internal grinding.

For Bore sizes smaller than 8 mm in diameter, it is not possible to use PCD tipped cutting tool inserts. In order to put a PCD tip into the carbide insert, material must be removed. This makes the insert weak and prone to breakage when it is clamped into the boring bar.

At the same time, clamping of small inserts into small boring bars becomes progressively more difficult as the bore size reduces.Top clamps trap swarf and, in order to fit inside the bore, become too small to exert enough clamping pressure. Screw locked inserts, while leaving space for swarf, require sufficient material under the insert for the thread of the clamping screw.

These problems are overcome by using brazed tools. The PCD tip is brazed directly to a tungsten carbide shank providing a rigid boring tool capable of remarkable surface finishes and providing a highly productive alternative to internal grinding.

Valenite Carbide Inserts for Stainless Steel

VALENITE INTRODUCES NEW TURNING GRADES FOR FINISHING, SEMI-ROUGHING STAINLESS STEELS

Valenite LLC has introduced two new tooling grades—expanding its targeted and application-specific lineup that allows users to better match machining operations and workpiece materials with tooling inserts for optimum production efficiencies, quality and economies. The new cutting technologies are the ValProTM VP8515 and VP8525 MT-CVD series of inserts. Both are being developed to augment the existing VP8535 grade and provide a complete range of turning capabilities for 304 and 316 stainless steels, Inconel and heat resistant alloys. The VP8515 is for finishing operations and the VP8525 is used for general duty semi-roughing/finishing. The existing VP8535 is for heavy metal removal tasks and roughing operations.

The VP8515 grade is set for high cutting speed (>200 m/min) at typical finishing

cut depths and has broad applicability with F5, M4, M6, M8, PM2, PM5 geometries. This grade is ideal for continuous turning of austenitic and duplex stainless steels at higher speeds providing reliable and predictable performance, with extended insert service life. Inserts using VP8515 grade have a thin yellow TiN outer coating for easy visual wear identification, an Al2O3 layer for thermal protection, a fine MT-CVD TiCN coating that helps to prevent flaking and reduces flank wear. Also incorporated in the tooling is a gradient area for added surface toughness, and a hard substrate offering greater resistance to wear and plastic deformation.

The TiCN/Al2O3/TiN coating is formulated specifically for turning of stainless steels and to resist sticking, notch wear and edge build-up, for enhanced hardness when hot.

The VP8525’s performance characteristics deliver high cutting speeds (>150 m/min) with mid- to large cutting depths...inserts have M4, M6, M8, R9, PM4, PM5 geometries to cover a myriad of cutting parameters. This grade is a basic choice for general duty M-class turning—continuous or intermittent cutting of austenitic and duplex stainless steels. These tools reduce the risk of plastic deformation and, like the VP8515, provide reliable performance and extended tool life. The VP8525 grade has similar coating technologies, layering and substrate construction as the finishing grade, including the TiCN/Al2O3/TiN coating for the efficient turning of stainless steels.

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Get carbide inserts or cutting tools for stainless steel machining at www.pgstools.com. PGS sells cutting tools and carbide inserts from Korloy, Taegutec, Valenite, Iscar and generic carbide inserts online at discount prices.

CNC Turning

To produce hubs, rods, bushes, pulleys and shafts, CNC turning is utilized where the lathe generates materials after inserting the single cutter point in to the material turning. The procedure of cutting is executed through a cutting tool which is applied either parallel or at right angle to the axis, of work piece. The tool may also be fitted at an angle relative to the work piece axis for the machining angles and tapers. The work piece may be of any cross section, but the machine surface should be straight and tapered.

There are various shapes available in CNC like pointed, simple, radius with profile added with threaded surface, curve and fillet. CNC machining is more economical than the CNC milling for producing the actual form through CNC turning. The material used for CNC turning possesses various qualities like material of work piece should be firm and can be of solid plastics. For the short running procedure of the mill, arrangements or alternative machine should be kept. CNC turning reduces the cost by minimizing the design elements.

CNC turning procedure is done through applying pressure on the work piece or the weaker material to form the flexible shapes of the material. Sometimes through CNC, the cut surface is formed by applying the helical feed as it results in rotation. The cutting procedure through which the work piece is eliminated from a material block by the help of the rotation of the tool is known as CNC milling. The work piece can rotate in perpendicular or circular way to produce different shapes and sizes. The cutting tool generally rotates in the CNC milling at an axis in a perpendicular form on the podium to generate various structures.

Variety of shapes that can be formed through CNC milling is 3D or 2D and some compound structured material. CNC milling for short procedure is also very economical. It is utilized to make different parts of engine, multifaceted mechanisms, enclosures and mold and custom tooling.

Thus, is a very effective procedure to make various machine parts of various shapes which is very significant for running the machine.

Get carbide inserts or cutting tools for your cnc machines at www.pgstools.com. PGS sells cutting tools and carbide inserts from Korloy, Taegutec, Valenite, Iscar and generic carbide inserts online at discount prices.

Author: George Ure

Article Source: http://www.articlesbase.com/sales-articles/cnc-turning-488912.html

What is a tool bit?

The term tool bit generally refers to a non-rotary cutting tool used in metal lathes, shapers, and planers. Such cutters are also often referred to by the set-phrase name of single-point cutting tool. The cutting edge is ground to suit a particular machining operation and may be resharpened or reshaped as needed. The ground tool bit is held rigidly by a tool holder while it is cutting.

Back Rake is to help control the direction of the chip, which naturally curves into the work due to the difference in length from the outer and inner parts of the cut. It also helps counteract the pressure against the tool from the work by pulling the tool into the work.

Side Rake along with back rake controls the chip flow and partly counteracts the resistance of the work to the movement of the cutter and can be optimized to suit the particular material being cut. Brass for example requires a back and side rake of 0 degrees while aluminum uses a back rake of 35 degrees and a side rake of 15 degrees.

Nose Radius makes the finish of the cut smoother as it can overlap the previous cut and eliminate the peaks and valleys that a pointed tool produces. Having a radius also strengthens the tip, a sharp point being quite fragile.

All the other angles are for clearance in order that no part of the tool besides the actual cutting edge can touch the work. The front clearance angle is usually 8 degrees while the side clearance angle is 10-15 degrees and partly depends on the rate of feed expected.

Minimum angles which do the job required are advisable because the tool gets weaker as the edge gets keener due to the lessening support behind the edge and the reduced ability to absorb heat generated by cutting.

The Rake angles on the top of the tool need not be precise in order to cut but to cut efficiently there will be an optimum angle for back and side rake.

Ref: http://en.wikipedia.org/wiki/Tool_bit

All About Cermet Inserts

Cermet inserts can't quite replace the coated carbide inserts in heavy roughing operations with interrupted cuts, but in semifinishing and finishing cermet inserts outperform carbide. They permit a higher surface speed while maintaining an acceptable surface finish with good tolerance holding property and increased tool life. Because the cermet surface is slick it presents less friction to the chip flowing over the cutting edge which decreases the possibility of build-up when machining high alloy steels and cold-formed, low-carbon steels. Cermet inserts are available from several suppliers with a wide selection of pressed-in chipbreaker configurations or ground-in chipbreakers.

The cermet inserts work at surface speeds from 100 to 1000 sfpm. On multi-spindle-automatics, positive inserts made of cermets avoid build-up encountered when running carbide inserts with low surface speeds. Also cratering is reduced due to the low heat transfer properties of the cermet material.

The recommended cutting speed for turning unalloyed steel with approximately 200 HB is 250 to 800 sfpm with 0.002" to 0.015" fpr and depth of cut of 0.004" to 0.150". Alloy steels up to hardness of 300 HB will have satisfactory tool life when machined between 200 and 600 sfpm with the depth of cut and feedrate mentioned above.

Face milling with cermet inserts can be achieved with the same cutting speeds as turning with chip loads per insert from 0.002" to 0.12". Milling is performed dry, while turning can be dry or with coolants.

Up to the present, cermets are widely used in Japan with good results in reducing machining costs. They deserve a greater consideration for material removal in the United States.

COPYRIGHT 1989 Gardner Publications, Inc.

Precision Cast Iron Machining

Whether you’re making brake discs and flywheels in grey cast iron, or crank shafts and wheel hubs in nodular cast iron, there is always a successful solution.

Over the years there have been a number of CBN grades made available for machining cast iron with CBN. Most notably are DR-80 and DR-85. These grades are made for the following applications:

For rough and semi-finish turning, milling, grooving and boring of hardened ferrous and certain softer ferrous materials:-

• Martensitic cast irons - Ni-hard - High chrome Chilled and heat treated cast irons
• Fully hardened cold-work tool steels
• Bearing steels
• High speed steels (continuous cutting only)
• Martensitic stainless steels
• Cobalt and nickel based hard facing alloys
• Fully pearlitic grey cast iron

DR-80 & DR-85 are high CBN content materials, diffusion bonded at the manufacturing stage to a tungsten carbide substrate.

DR-80 is (80% CBN) has a greater particle size than DR-85, (85% CBN). DR-80 is better for hardened steel, but DR-85 has better wear characteristics when machining cast iron with CBN, particularly when the stucture contains Ferrite.

For more information on machining with CBN Inserts
please visit David Richards Engineering UK or
David Richards Engineering US

Hard Turning with CBN

CNMA 432 Quad Edge CBN Insert Shown

Hard turning with CBN will:

• Reduce Grinding Investment
• Increase Tool Life
• Reduce Cost with Faster Cycle Times
• Lower Tool Change Down Time Costs
• Reduce Scrap Cost
• Reduce By-Product Disposal
• Extend Tool Life In High Production Hard Turn Applications
• Increase Thermal and Mechanical Shock Resistance to Handle the Most Demanding Contouring and Interrupted Cuts

Hard turning requires switching from carbide to CBN inserts. It’s easier and more economical than one would expect. The major adjustment is working with much higher surface speeds.

Earlier posts that deal with CBN Insert questions:

CBN Insert Applications

What is PCBN?