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Carbide Insert Identification Chart

Carbide insert identification chart is now available at www.pgstools.com. This chart is helpful for identifying inserts without a home.

The insert identification chart is located here:

Carbide Insert ANSI Designation

CBN Cutting Tools for Grooving

Hard part grooving can be a difficult process without the correct tools. CBN cutting tools for grooving can ease that process. During heat treatment, many features of machined components suffer distortion. If the position or dimensions of a groove are critical to the performance of a hardened component, David Richards can offer a simple solution to this problem - ‘Hard Grooving’. Based on the Top Notch system, David Richards supply grooving tools in a wide range of sizes from 0.5 mm width upwards. David Richards supply tools for circlip and ‘O’ring grooves with controlled corners or full radii, either full form for plunging or undersize for profiling.

Using such surface speeds typical for turning, grooves are machined at low feed rates (0.01 / 0.05 mm/rev). The low feed rate ensures that the swarf is very weak and brittle, decreasing the likelihood of it breaking the tool. Where there are no interruptions to the cutting path, coolant should be used to aid evacuation of the swarf and ensure that the component remains at a stable temperature for ease of measuring. If the cutting path is interrupted, an air blast will serve the same purpose without the risk of thermally shocking the PCBN tool.

If practical, it is better to finish a groove that has been pre-formed at the soft stage. This ensures uniform hardness around the groove and maintains the structural integrity of the component. However, if it is acceptable, satisfactory results are achieved grooving through a hardened layer into the core material. Successful applications include grooving case hardened (58 / 63 HRc) splined shafts and gear teeth, internal circlip grooving hardened EN31 (58 / 60 HRc)
bearing components, and producing profiles in the face of D2 tools steel tools using Full radii face grooving tools. All operations that would be time consuming and difficult to grind.

Whilst the Top Notch system offers an ideal base for most grooving tools, other systems have been employed with excellent results.

It naturally follows that, since David Richards can produce tools for ‘Hard Grooving’ full and partial form cbn threading tools, both external and internal, are available for ‘Hard Threading’. Where the pitch of the thread is large, or the diameter of the component is small, it must be remembered that the feed rate required, at the required surface speed for ‘Hard Turning’ will be relatively fast. But, producing a 90 mm diameter internal stub Acme thread 150 mm deep,
with a 6 mm pitch in 58 HRc Ni-Hard iron, at 120 m/min from blank bore, though somewhat exciting, proved a major cost saver.

To purchase CBN Grooving Inserts please visit

www.pgstools.com

Machining Soft Steels with CBN Inserts

Finding it difficult to machine soft steels with cbn inserts? I would suppose that soft steel is relative, so generally speaking, cbn inserts will machine steels from 45-65 HRc. For soft steels (the ones on the lower end of the 45-65 HRc), the lower you are on the hardness scale, the faster you will want to machine the material.

CBN needs heat to cut at its fullest potential. A quick lesson: CBN generates heat in the shear zone, thus locally anealling the material, cutting it as if it were soft.

If you are having trouble with turning using CBN inserts or PCD inserts, please call to discuss your application with David Richards Engineering or email to sales@drengus.com

Purpose and Use of the Cut-Off Tool and Holder

After completing a part in the lathe it is frequently necessary to separate the part from the excess material used for chucking. This operation is best accomplished with the use of a cut-off tool or "parting tool" as it is sometimes called. The Cut-off Tool and Holder consists of a very slender high speed tool steel cutting blade mounted in a special tool holder. The thinness of the blade (.040") enables it to feed into the part quite easily and at the same time minimizes the amount of waste material. The turning speed for parting should be approximately one half the normal turning speed for any given material. One word of caution; never use a parting tool on a part mounted between centers. The part may bind on the cutter and result in a scrapped part or a broken cutting tool.

Parting off material (free machining) over a 1.00" (25mm) diameter will always present problems on a machine of this size.

Always try to lay work out so the cut-off tool is used as close to the spindle as possible. Set blade height by sliding the blade in its slot in the tool holder. It should be set so the tip is aligned with the centerline of the part being cut. An unusual diameter may require a shim to be placed under the front or rear of the holder to accomplish this.

NOTE: ALWAYS USE CUTTING OIL WHEN USING THE CUT-OFF TOOL. The cut will be made much smoother, easier and cooler.

Speed should be slower than normal turning speed and feed rate should be a little heavy so the chip will not break up in the slot. If speed and feed are correct, there will not be any chatter, and the chip will come out as if it were being unrolled. Coolant (cutting oil) plays a major roll in this occurring properly.

If the tool chatters, first check to see if the work is being held properly. Then decrease speed (RPM) or increase feed rate or both. Once the blade has chattered, it leaves a serrated finish which causes more chatter. Sometimes a serrated finish can be eliminated by turning the spindle off, adding a liberal amount of cutting oil, bringing the blade up so there is a slight pressure on it without the spindle turning, and then turning by hand or as slowly as possible with the speed control.

BY: Joe Martin

Where to use ceramic inserts and silicon nitride inserts

All Irons... use silicon nitride in all applications...turning, boring, milling & facing. Use for roughing, semi-roughing, semi-finishing & finishing applications. Generally speaking, silicon nitrides can be used in all iron applications.

All Irons... use the black (CC-20) and/or white (CC-10) ceramic on semi-finishing & finishing applications. They are less costly and harder than silicon nitride (more abrasion resistant & longer lasting).

Steels below Rc58 in hardness... use the black (CC-20) and/or white (CC-10) ceramic in almost every semi-finishing & finishing applications. They can even cut with mild interruptions. If your customer isn't using CC-10 & CC-20 on almost every finishing application, he's losing money.

Steels above Rc58 in hardness... use the black (CC-30) for finishing applications, especially to replace grinding. You can also use silicon nitride for roughing.

Aerospace Metals... Inconel, Hasteloy, Waspeloy, Renee, Etc. For roughing or finishing use CC-5477 Silicon Nitride specifically designed for these materials.

Click on the link below for tools:

Ceramic Inserts

Carbide Insert for Turning Wood

We have found that this insert performs quite well for turning wood. There are two choices available for chipbreakers. In the first picture is the "TA" and the "HA" is in the second picture. Each one serves a different purpose, so read carefully. Both inserts are from Korloy. These inserts are available in packs of 2. For pricing on carbide inserts for turning wood: www.pgstools.com

Recently added to the collection are these carbide inserts for cutting wood:

http://www.pgstools.com/servlet/the-Carbide-Inserts-cln-Wood-Cutting/Categories