“When customers come to us for grooving tools, it is usually for a turnkey operation” — that is, a job for which Mikron produces most if not all of the different tools needed to make a part, said Sales Manager Nathan Lisker.

Please contact Gühring directly for reconditioning inquiries for non-Gühring manufactured variable flute designs.

When customers ask why they should pay more for Jet-Cut holders, he points out that coolant pinpointed on the cutting edge increases tool life, which translates into more parts per edge. He notes as well that efficiently delivered coolant quenches chips and makes them brittle, so they break up more easily.

Upgrades and new equipment investments Continuous improvement, maximum quality and productivity are some of the principles by which Gühring operate. In this regard, Gühring South Africa has invested heavily in making sure it can deliver on these morals. Continued Green: “Recently Gühring South Africa has added a new cylindrical grinder, an energy efficient compressor, as well as a wheel dressing machine capable of dressing single and multiple wheel packs, thus improving efficiency.”

Coolant Ring Technology holders allow better coolant penetration into a bore during cutting operations. Image courtesy of Scientific Cutting Tools

With inserts like this, “you can plunge down and then start side-turning to remove material as well,” he said.

William Leventon is a contributing editor to Cutting Tool Engineering magazine. Contact him by phone at 609-920-3335 or via email at wleventon@gmail.com.

Another is the variety of coolant-through tooling options available. As the name suggests, this type of tooling features internal passages for coolant flow. White said many different toolholders feature coolant-through designs that get coolant right to the cutting edge to lessen thermal degradation of the substrate.

Shops can get off to a good start with grooving by making sure the tool in the lathe turret is perpendicular to the workpiece surface.

“It is therefore worthwhile to obtain information about the possibilities of reprocessing the tools when buying new tools. Because the regrinding of tools offers you the following advantages:

“These can be challenging if they are at the bottom of a small-diameter hole,” he said. “You’ve got to have the proper reach to get to the groove (location) and then be able to machine it successfully.”

“Our free pick-up and drop-off service even picks up your used tool from you and after seven to 10 working days you will get it back reconditioned. This fast implementation is only possible through short distances.”

“Gühring offers a complete reconditioning service for carbide end mills, including refurbishing of used tools and the addition of corner radius. In addition to standard helix end mill designs, our reconditioning division can also recondition Gühring variable flute and variable helix carbide end mills,” explained Gerald Green, Managing Director of Gühring Cutting Tools South Africa.

Fluid that reduces temperature buildup at the tool/workpiece interface during machining. Normally takes the form of a liquid such as soluble or chemical mixtures (semisynthetic, synthetic) but can be pressurized air or other gas. Because of water’s ability to absorb great quantities of heat, it is widely used as a coolant and vehicle for various cutting compounds, with the water-to-compound ratio varying with the machining task. See cutting fluid; semisynthetic cutting fluid; soluble-oil cutting fluid; synthetic cutting fluid.

“If (the tool) is going on a lathe, our message is to use coolant-through tooling as a first choice,” said East, whose company offers tooling products of this type called Jet-Cut.

In some instances, he said, “a coated tool is only a few dollars more than an uncoated one. But in the right materials, it can give you three to five times the tool life of an uncoated tool. So you get a great return for a small investment in the tool.”

Turning machine capable of sawing, milling, grinding, gear-cutting, drilling, reaming, boring, threading, facing, chamfering, grooving, knurling, spinning, parting, necking, taper-cutting, and cam- and eccentric-cutting, as well as step- and straight-turning. Comes in a variety of forms, ranging from manual to semiautomatic to fully automatic, with major types being engine lathes, turning and contouring lathes, turret lathes and numerical-control lathes. The engine lathe consists of a headstock and spindle, tailstock, bed, carriage (complete with apron) and cross slides. Features include gear- (speed) and feed-selector levers, toolpost, compound rest, lead screw and reversing lead screw, threading dial and rapid-traverse lever. Special lathe types include through-the-spindle, camshaft and crankshaft, brake drum and rotor, spinning and gun-barrel machines. Toolroom and bench lathes are used for precision work; the former for tool-and-die work and similar tasks, the latter for small workpieces (instruments, watches), normally without a power feed. Models are typically designated according to their “swing,” or the largest-diameter workpiece that can be rotated; bed length, or the distance between centers; and horsepower generated. See turning machine.

In addition, a nearby complex in Sigmaringen-Laiz is home to four vital aspects of Gühring’s business: R&D, OEM support, the manufacture of carbide tools and taps and apprentice training. In its tap and threadmill manufacturing plant alone, 60 000 taps are manufactured from start to finish every week.

Gühring South Africa first opened its regrind facility in Port Elizabeth, Eastern Cape in late 1999. The 180m² factory served its purposes until a new 873m² factory was built in 2010 in the Greenbushes area of Port Elizabeth and the company moved to these facilities.

It’s worth regrinding! “Take, for example, the solid carbide deep hole drill RT 100 T from Gühring: This is a deep hole drill with internal cooling and a TiAIN coating. For the example, we have chosen the common dimension with a diameter of 10mm and a diameter-length ratio of 25xD. Depending on wear, the tool can be reground three to five times.”

“The cost of a new tool plus three regrinding of this tool is far below the cost that would be incurred for four new tools in the same period. In this way, you can reduce the cost per tool by more than half with repeated regrinding. The diagram illustrates how tool costs are reduced with each regrind.”

When a groove is very wide, White warns that cutting it all at one time can put too much pressure on the tool, causing deflection problems and even breakage. So in cases like this, he believes that a better approach can be to employ a peck cycle — in other words, making a couple of passes to depth using a tool that’s thinner than the groove, then moving the tool over a little and doing the same again. Besides going easier on the tool, he said a peck cycle gives a chance to flush out potentially problematic chips.

“Even if the groove was wider than it was deep,” he said, “if it had 90-degree corners, you would take a groove tool and plunge all of that material out. Today, we want to apply a groove/turn solution in these cases.”

Many part designs include a chamfer at the top of the groove to eliminate burrs. In these cases, shops can opt for grooving inserts that incorporate chamfering, said Coomer, whose company makes such inserts. By cutting the groove and chamfer at the same time, users eliminate a secondary operation to create the chamfer when the groove is finished.

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Substance used for grinding, honing, lapping, superfinishing and polishing. Examples include garnet, emery, corundum, silicon carbide, cubic boron nitride and diamond in various grit sizes.

For deep grooving applications, the company typically produces solid-carbide tools because of their superior rigidity. White pointed out that the allowable length-to-diameter ratio for carbide tools is 10-1 compared with 3-1 for indexable toolholders made of steel.

Machining operation in which material is removed from the workpiece by a powered abrasive wheel, stone, belt, paste, sheet, compound, slurry, etc. Takes various forms: surface grinding (creates flat and/or squared surfaces); cylindrical grinding (for external cylindrical and tapered shapes, fillets, undercuts, etc.); centerless grinding; chamfering; thread and form grinding; tool and cutter grinding; offhand grinding; lapping and polishing (grinding with extremely fine grits to create ultrasmooth surfaces); honing; and disc grinding.

For further details contact Gühring South Africa on TEL: 041 372 2047/46/43/38 or email info@guhring.co.za

Gottlieb Gühring started the company with 17 employees manufacturing a small range of twist drills, spirit levels, screw clamps, fastening chains and plumb bobs. In 1964, the current owner and Gottlieb’s grandson, Dr Jörg Gühring joined the company. Today, Oliver Gühring represents the fourth generation of the family, sitting alongside his father as part of a four-man executive board and taking responsibility for sales and marketing activities.

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Groove or other tool geometry that breaks chips into small fragments as they come off the workpiece. Designed to prevent chips from becoming so long that they are difficult to control, catch in turning parts and cause safety problems.

Grooving also goes better these days thanks to advances in tool coatings. The latest coating materials are heat- and wear-resistant, which increases tool life. White said they additionally improve speeds and feeds by preventing workpiece materials from sticking to tools.

East said groove/turn operations used to require two things. One was that CAD/CAM companies had to be pressed to create code for the work. Also, he said a special type of insert was needed, one with a chipformer on the front for plunging, plus a chipformer on each side for turning.

Among the coatings that Scientific Cutting Tools uses for grooving tools are diamondlike carbon coatings, such as ta-C, which he describes as a very hard, thin coating that works well on tools used to cut abrasive nonferrous materials.

Another timesaving option he recommends is using a multigroove tool to cut multiple grooves right next to each other. To simultaneously cut four adjacent grooves, for example, shops can use an insert with four adjacent cutting edges.

Provided with a part drawing or the part itself, Mikron will grind a tool designed for the special form or profile to be grooved into the part.

“Why should you have your tool reconditioned when it reaches the end of its lifetime? There are several reasons for this: On the one hand, we owe it to the environment to use resources sparingly, because the global stocks of raw materials for carbide tools (cobalt and tungsten) are limited. On the other hand, reprocessing also makes sense in terms of economic efficiency,” said Green.

Substances having metallic properties and being composed of two or more chemical elements of which at least one is a metal.

If the chipbreaker doesn’t, Coomer said, “the chips will get stuck, especially once you get down into the groove a little bit. This will cause some marring of the parts.”

Further additions include a new laser engraving machine and Green says: “We are also upgrading the coating facility with a new coating plant including ancillary equipment such as an automated washing machine, etc. This equipment has started arriving and should be complete during the third quarter of 2022.”

If chamfers are on the top of the grooves, Coomer said the insert can be modified to create those features as well, “so you can cut all four grooves and put chamfers on them in one shot.”

East said one reason to opt for a groove/turn operation is that chip control is easier when turning than when plunging. In addition, he said groove/turn processes reduce cycle time because metal removal rates are usually “a lot better” than those achieved with plunging.

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62% cost savings by regrinding your tools “Used tools like new again – this is what we offer you through our regrinding service. In our regrinding centre, we restore the original geometries and layers of the worn tools and thus also their original performance. This allows you to reuse tools instead of replacing them and reduce your total cost of ownership: For some Gühring tools, the cost savings due to regrinding are up to 62 per cent!”

Lisker said coolant-through technology is especially helpful when cutting nickel-base alloys like Inconel that transfer heat back to the tooling. Besides maintaining thermal stability on the cutting edge, he said coolant-through systems disperse chips to help with chip control.

A single insert also can be used to combine grooving and turning processes. This wasn’t the case back when East worked at a machine shop.

Same quality – four times the service life “When it comes to the quality of the final product, there is no difference between the first regrind and the third regrind at Gühring. Our regrinding centres are equipped with the same grinding machines and coating systems as the new production facilities and as a tool manufacturer, Gühring knows all the parameters needed for the regrinding of your tools. This is how the regrinding is done with the original geometries and layers. You will receive a new tool with which you can continue working with the same cutting values and achieve identical results.”

Mikron works with customers to produce the best solid-carbide grooving tools for applications. Image courtesy of Mikron

It’s worth regrinding! “Take, for example, the solid carbide deep hole drill RT 100 T from Gühring: This is a deep hole drill with internal cooling and a TiAIN coating. For the example, we have chosen the common dimension with a diameter of 10mm and a diameter-length ratio of 25xD. Depending on wear, the tool can be reground three to five times.”

Gühring has a presence now in most countries throughout the world. There are 46 sales companies globally, 31 production plants and 47 service centres and the tooling range has grown significantly comprising some 1 850 tool types, including 45 000 standard tools.

Fourth generation Founded in 1898, Gühring has successfully evolved to take the place as one of the leading manufacturers and suppliers of rotary cutting tools.

Workpiece is held in a chuck, mounted on a face plate or secured between centers and rotated while a cutting tool, normally a single-point tool, is fed into it along its periphery or across its end or face. Takes the form of straight turning (cutting along the periphery of the workpiece); taper turning (creating a taper); step turning (turning different-size diameters on the same work); chamfering (beveling an edge or shoulder); facing (cutting on an end); turning threads (usually external but can be internal); roughing (high-volume metal removal); and finishing (final light cuts). Performed on lathes, turning centers, chucking machines, automatic screw machines and similar machines.

“If you can’t get the chips out of the bore,” White said, “usually you will re-cut them, and then they will scar the surface.”

“Investing in a new tool every time you notice wear is expensive – and also unnecessary for many solid carbide tools. Because the quality of the tool core and the cutting material has not changed. Only the cutting edges need to be sharpened. The cost of such regrinding represents only a fraction of the purchase price for a new tool.”

He recommends running an indicator along the length of the tool to check perpendicularity. For a 102 mm (4") tool length, the measurement should be off by no more than about 0.1 mm (0.004"), he said.

Common grooving options today include solid-carbide tools and indexables. When it comes to grooving, the focus at Scientific Cutting Tools Inc. in Simi Valley, California, is mainly on grinding solid-carbide tools for cutting internal grooves for things like threads and O-rings, said Sales Director Todd White.

Headquartered in Albstadt, Germany, Gühring has three facilities in this area: the original building where the business began which still manufactures HSS drills and special tooling; a fully functional PCD design and manufacturing facility; and a recently acquired factory in Onstmettingen that is used exclusively for the assembly, service and support of its own range of grinding machines.

• Restoration of original quality • 100% performance • Increase in profitability • Conservation of resources and the environment

Gühring South Africa has recently added a new cylindrical grinder, an energy efficient compressor, as well as a wheel dressing machine capable of dressing single and multiple wheel packs to their facility in Port Elizabeth

“And when your tool is finally worn out, we will even buy back the carbide from you – to recycle it,” concluded Green.

Chip problems like these can be prevented by improved coolant delivery, which is possible today thanks to several developments. One is the increased coolant pressures produced by current machines. White said these pressures typically range from 300 psi all the way up to 1,000 psi.

When indexable tools are used for grooving, “many times your chipbreaker is a big key to success,” said Travis Coomer, national key account manager at GWS Tool Group in Tavares, Florida.

When a grooving operation is required, don’t plunge in without giving careful thought to what you’ll be using and how to go about the task. Specific items that should be considered include proper preparation, tool and process options and what the latest technology has to offer. Time spent upfront on these important topics can pay off in longer tool life, faster cycle times and better grooving results.

If the groove to be cut isn’t too deep, he believes that Top Notch-style inserts may be a good choice. These feature molded notches on the top and bottom that seat the inserts in their holders. With the inserts held at a 3-degree angle, the notches pull them back into the pocket during cutting, he explained, making the system very rigid and stable.

He advises those who use inserts to cut grooves to make sure the chipbreaker folds the chip in a way that makes it smaller than the groove being cut.

Machining grooves and shallow channels. Example: grooving ball-bearing raceways. Typically performed by tools that are capable of light cuts at high feed rates. Imparts high-quality finish.

If the tool isn’t, “the edge of your tool is going to be tilted, so you could potentially be running scrap parts,” said Clay East, national product manager for grip systems at Iscar Metals Inc. in Arlington, Texas.

“Our free pick-up and drop-off service even picks up your used tool from you and after seven to 10 working days you will get it back reconditioned. This fast implementation is only possible through short distances.”