Archive for April, 2009

Tensilgrind for Hard Metals

April 23, 2009

Tensilgrind is a precision contour grinding machine designed for the preparation of physical test specimens from high hardness metal foil and sheet. Tensilgrind employs the basic principle of Tensilkut, wherein a precision master template is manually guided across the table surface with the removal of metal accomplished in a series of light grinding passes.

Tensilgrind for Hard Metals

Tensilgrind for Hard Metals

Tensilgrind is designed to be located in the metallurgical laboratory, so it is available for grinding test specimens as they are needed, rather than waiting for them to be finished by a machine shop in days or weeks. Laboratory personnel without previous machining experience can readily grind specimens from hard metals and super alloys, resulting in a greatly reduced per specimen cost.

The formed grinding wheel with a ½” hub shaped to a 5/16” width obtains minimum wheel contact with the specimen, while providing maximum wheel rigidity. A radius dressed on the periphery of the wheel by a built in diamond wheel dresser reduces the contact of the wheel with the specimen to a small point for minimum generation of heat.

Tensilgrind control head and Grinding Wheel

Tensilgrind control head and Grinding Wheel

Tensilgrind templates are interchangeable with the Tensilkut machines, enabling the user of both machines to have just one set of templates. Accordingly, the Tensilgrind is offered with three different control head heights, although the maximum capacity of any machine is the same. The limitation on the thickness of the material which can be prepared on the Tensilgrind is caused by the radius of the grinding wheel, which would imprint upon too thick a sample.

Earth Day at Tensilkut

April 22, 2009

When Tensilkut bought our current building in 1986, it was rather plain.  It was a nice, attractive building on 5 acres, located on a prime corner in the county’s premier industrial park.  However, there was no landscaping, and the lawn had an enormous soggy area in the middle.

Tensilkut is a small company.  We always have been, and always will be.  That, however, does not mean that we must have an unpleasant work environment.  With that in mind, during the late fall of 1986, we were able to hire a local farmer to excavate the lawn where the wet spot was, and put in a small pond.

On Earth Day 1987,  everyone at Tensilkut went outside and planted trees and shrubs.  Well, maybe the men planted and the women delivered many pitchers of iced tea and issued numerous compliments about the men’s planting, but it was a nice day nonetheless.  Since then, we’ve planted a new tree every Earth Day.  Often we picnic outdoors, and sometimes spouses come join us for lunch.  It is a very nice place indeed.

The Tensilkut Building

The Tensilkut Building

I am pleased to show you our 2009 Earth Day tree, a flowering cherry tree.

Tensilkut cherry tree

Tensilkut cherry tree

Sit back, relax, and enjoy a tree today.

CNC Tensilathe

April 16, 2009

Bill Gates has done many wonderful things for the world.  Obviously, he brought the ability to use computers to the masses, which has expanded employment throughout the world in related fields.  Without Bill’s contribution to the computer world, it’s likely that the Internet as we know it wouldn’t exist, because consumers wouldn’t be able to use it.

From the personal perspective of anyone reading this entry, however, one of the great things Bill Gates has indirectly influenced is the ability of laboratory personnel to automatically turn round test bars.  Without Bill, we’d still be back in the days when CNC machine operators had to attend special “CNC School” for months, and each machine cost around $100,000.

The CNC Tensilathe is the only laboratory-sized, automatic lathe designed specifically for turning round tensile bars from most machinable materials.

CNC Tensilathe

CNC Tensilathe

With its dependable, 1-1/2HP, 180VDC motor, the CNC Tensilathe will prepare specimens from round or irregular stock; full sized or subsized tensile, fatigue and similar round test samples can be accomplished. It was developed for operation by lab personnel with no previous machining experience, and operates on a Windows based microcomputer. The CNC Tensilathe uses a standard 3-jaw chuck to hold the specimen; the opposite end is center drilled to accommodate a live center. Samples from approximately 1/4” to 2” diameter can be completed, using round or irregular starting blanks; the finished specimens are accurate to within +.0005”, and will have a 32 or better surface finish, depending upon the material. A built-in micro-drop coolant system increases cutter life and improves surface finish, while the moveable chip shield over the working area reduces flying chips. An emergency stop switch is mounted on the front of the lathe, as are all power switches. The CNC Tensilathe is shipped fully set up; the computer must be hooked up, and the machine is ready to operate.

Turning a sample with the CNC Tensilathe

Turning a sample with the CNC Tensilathe

As with all Tensilkut machines, the CNC Tensilathe comes with a self instruction manual; training is available in our facility at no extra cost.  The machine is programmed for the user, and shipped with all sample contours ordered pre-installed into the computer.  Additional specimen programs can be added later.

Tensilathe/505

April 9, 2009

Turning round tensile bars has always been, at best, a laborious process.  In the mid-1980’s, however, our customers began to ask for a machine to enable them to turn their bars in the lab.  While Tensilkut had long made preparation of flat bars easy, round test bar turning hadn’t been brought into to the laboratory’s realm.

In the late 1970s, companies had begun downsizing their personnel, and automating many aspects of production.  Part of this was due to the retirement of the World War II era production workforce.  Regardless of the causes, there were suddenly fewer machinists to prepare test specimens for labs.  At the same time, customers began demanding that companies do more testing of their products – raw material and components of finished products.  With the rise in demand for the capability to turn round test bars in the lab, the concept of the tracing lathe dedicated to test specimens, and easy enough for lab technicians without extensive machinist training to run became a reality.

Tensilathe/505

Tensilathe/505

The Tensilathe/505 is a precision, hydraulic tracing lathe.  It traces the contours of the specimen into the bar using a template manufactured by Tensilkut Engineering, which contains the exact lengths of the gauge section, reduced section, and grips.  Since it’s a hydraulic lathe, the movement both left to right and forward and backward of the cutting tool is very smooth, ensuring an even transition from reduced section to radius.  The lathe uses standard tooling, so it’s easy to match the tooling being used to the material being cut.

The Tensilathe is not fully automated.  The tracer moves back and forth without operator involvement beyond starting the cutting cycle, but the customer must turn the micrometer knob to dial in the depth of each cut.  There is a stop which can be reset, so the user need only keep track of the size of the first bar of a given size; thereafter, he can set the stop to prevent the bar from being cut undersized.  Of course, each bar should be checked to insure that it is the correct diameter in the gauge section before testing.

Tensilathe/505 tracing head

Tensilathe/505 tracing head

CNC Tensilkut III

April 7, 2009

When one thinks of CNC machining, what comes to mind? A great big machine requiring months of CNC schooling, run by a highly trained individual who does things when he can, and not when someone else necessarily wants them.

That’s not the case with the CNC Tensilkut III.

Designed to be used by people familiar with the operation of computers running Windows, the CNC Tensilkut requires minimal skills of its operator. The machine is sized for placement in the lab, to be used by the operator of the testing machine and any other lab equipment in the same vicinity.

When the CNC Tensilkut III is ordered, specimen programs are ordered at the same time, so they can be installed at the time the machine is built. Any specimens installed on the machine are located in a drop down menu, and selected by the operator. The greatest mechanical aptitude required is the use of allen wrenches to tighten the material clamps, and of standard wrenches to change the cutting bit. Included in the machine is a mist coolant system, to simultaneously cool and lubricate the edges of the specimens, resulting in improved surface and increased cutter life. Also built in is a vacuum chip reduction system. While it doesn’t collect all of the chips, it does significantly reduce the number of chips remaining within the cabinet of the machine.

The CNC Tensilkut III can be set up to cut flat tensile specimens from strips or plaques of metals and non-metallic materials. Programs we’ve written for customers have included tensile, flexural, fatigue, and tensile impact bars and blanks to be notched for charpy and izod impact tests.CNC Tensilkut III

For easy, automated preparation of test specimens on your lab’s schedule, the CNC Tensilkut III is an excellent, reasonably priced system.

Tensilkut II

April 2, 2009

For the first 30 years of this company’s existence, the Tensilkut I was the only machine for preparing flat tensile bars. It worked very well, of course; but at trade shows, the comment could often be heard, made by passers-by, “That’s a Tensilkut. Great machine. Noisy little thing.” And it was. For many years, customers inquired as to whether Tensilkut Engineering had plans to offer a soundproofed version of the machine.

In 1984, the company’s founder retired, and management was free to react to the customers’ stated desires. In 1985, the Tensilkut II was designed. The premise that the machine would be manually operated, as was the original version, but less objectionable in the lab, was the driving force behind the design. In the spring of 1986, the Tensilkut II was introduced at the Quality Expo in Chicago. There was a great deal of interest in the machine, and many users of the original machine upgraded to the newer version.

While the operational procedures are the same, the Tensilkut II contains many features which are either optional or unavailable on the Tensilkut I. Most obvious, of course, is the sound reduction package. The base of the machine is wrapped in the same soundshield used in music recording studios, and the control head is enclosed by a plexiglass shield around all sides save the front. A footswitch makes turning the machine on and off much easier, and all switches are located on the front of the machine for ready access. The machine also includes the Tensilvac chip reduction system, Tensilmist and motor speed regulator, all of which are optional on the Tensilkut I.

In 1987, after the company moved to its current location in Maryville, Tennessee, we ran an experiment. One of the men who worked at Tensilkut drove a 1973 Toyota pickup truck with no muffler, and someone else drove a 1 year old Cadillac Coupe de Ville. We measured the decibel readings for both the Tensilkut I and Tensilkut II with the motors on, but not cutting anything. The Tensilkut I had the same decibel reading as the Toyota, while the Tensilkut II generated the same noise as the new Cadillac, when the sound meter was right next to the hood.

This experiment, of course, lent credence to customers’ statements to the effect that they had to build a small room around their Tensilkut I machines to make the noise tolerable.

Tensilkut II

Tensilkut II

Tensilkut I

April 1, 2009

Every great invention, widely used or not, is born of someone’s need, and his or her ability to create a solution to that problem or need. The Tensilkut is one such invention. Created by a metallurgist working for a major corporation in 1954 when he encountered delays in getting his physical test specimens prepared by his company’s machine shop, the man soon patented his machine and struck out on his own.

The Tensilkut I is nearly identical to the machine created back in 1954. It is a precision milling machine designed specifically for machining flat tensile samples from metals and non metallics. Tensilkut machined specimens are free of induced heat or cold working distortion, and create test samples accurate to within +/-.0005″, when used with a Tensilkut template and cutter.

The test strip is clamped in a precision template which is manually moved across the Tensilkut table during the machining of the test specimen. The depth of cut is controlled by a micrometer control knob located on the control head. Specimens are cut in a series of light passes – the depth of each cut will depend upon both the material and its thickness. Of course, for the final passes, the recommended depth of cut is .0005″ to .001″. When the sample is machined to its final gauge width, the control head will reach a stop, and prevent further machining of the specimen. Additionally, the Tensilkut template assures repeatability of the specimens, so variations in test results will be caused by variations in the material.

In the past 50 years, tensile bars prepared on a Tensilkut machine have become the benchmark, as they have been proven to be the most rapid, economical and repeatably accurate samples a testing laboratory can use.

Tensilkut I

Tensilkut I