Archive for the ‘Round Test bars’ Category

ASTM E8 Threaded Tensile Bars

October 16, 2013

ASTM E8 threaded tensilesThese round tensile bars to ASTM E8 were turned with the CNC Tensilathe, using the optional threading package.  The larger bar is the standard .505″ x 2″ gauge section; the smaller is the .250″ x 1″ subsized ASTM E8 specimen.

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